09. module.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 模块\n",
    "在前面的几个章节中我们脚本上是用 python 解释器来编程，如果你从 Python 解释器退出再进入，那么你定义的所有的方法和变量就都消失了。\n",
    "\n",
    "为此 Python 提供了一个办法，把这些定义存放在文件中，为一些脚本或者交互式的解释器实例使用，这个文件被称为模块。\n",
    "\n",
    "模块是一个包含所有你定义的函数和变量的文件，其后缀名是.py。模块可以被别的程序引入，以使用该模块中的函数等功能。这也是使用 python 标准库的方法。\n",
    "\n",
    "下面是一个使用 python 标准库中模块的例子"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "命令行参数如下:\n",
      "d:\\python36\\lib\\site-packages\\ipykernel_launcher.py\n",
      "-f\n",
      "C:\\Users\\bhe\\AppData\\Roaming\\jupyter\\runtime\\kernel-a46a9524-4fac-44aa-8214-42b9cfe244a1.json\n",
      "\n",
      "\n",
      "Python路径为： ['', 'd:\\\\python36\\\\python36.zip', 'd:\\\\python36\\\\DLLs', 'd:\\\\python36\\\\lib', 'd:\\\\python36', 'd:\\\\python36\\\\lib\\\\site-packages', 'd:\\\\python36\\\\lib\\\\site-packages\\\\ner-0.1-py3.6.egg', 'd:\\\\python36\\\\lib\\\\site-packages\\\\win32', 'd:\\\\python36\\\\lib\\\\site-packages\\\\win32\\\\lib', 'd:\\\\python36\\\\lib\\\\site-packages\\\\Pythonwin', 'd:\\\\python36\\\\lib\\\\site-packages\\\\IPython\\\\extensions', 'C:\\\\Users\\\\bhe\\\\.ipython'] \n",
      "\n"
     ]
    }
   ],
   "source": [
    "import sys\n",
    "print('命令行参数如下:')\n",
    "for i in sys.argv:\n",
    "    print(i)\n",
    "\n",
    "print('\\n\\nPython路径为：', sys.path, '\\n')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "1. import sys 引入 python 标准库中的 sys.py 模块；这是引入某一模块的方法\n",
    "2. sys.argv 是一个包含命令行参数的列表\n",
    "3. sys.path 包含了一个 Python 解释器自动查找所需模块的路径的列表"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## import语句\n",
    "想使用 Python 源文件，只需在另一个源文件里执行 import 语句，语法如下\n",
    "<br>import module1[, module2[,... moduleN]\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "当解释器遇到 import 语句，如果模块在当前的搜索路径就会被导入。\n",
    "\n",
    "搜索路径是一个解释器会先进行搜索的所有目录的列表。如想要导入模块 support，需要把命令放在脚本的顶端："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello :  123\n"
     ]
    }
   ],
   "source": [
    "# %load ./code/support.py\n",
    "def print_func(par):\n",
    "    print (\"Hello : \", par)\n",
    "    return\n",
    "\n",
    "print_func('123')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello :  world\n"
     ]
    }
   ],
   "source": [
    "%run ./code/support.py"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "def print_func(par):\n",
      "    print (\"Hello : \", par)\n",
      "    return\n",
      "\n",
      "print_func('world')\n"
     ]
    }
   ],
   "source": [
    "import os\n",
    "with open('./code/support.py', 'r') as file:\n",
    "    print(file.read())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Help on module os:\n",
      "\n",
      "NAME\n",
      "    os - OS routines for NT or Posix depending on what system we're on.\n",
      "\n",
      "DESCRIPTION\n",
      "    This exports:\n",
      "      - all functions from posix or nt, e.g. unlink, stat, etc.\n",
      "      - os.path is either posixpath or ntpath\n",
      "      - os.name is either 'posix' or 'nt'\n",
      "      - os.curdir is a string representing the current directory (always '.')\n",
      "      - os.pardir is a string representing the parent directory (always '..')\n",
      "      - os.sep is the (or a most common) pathname separator ('/' or '\\\\')\n",
      "      - os.extsep is the extension separator (always '.')\n",
      "      - os.altsep is the alternate pathname separator (None or '/')\n",
      "      - os.pathsep is the component separator used in $PATH etc\n",
      "      - os.linesep is the line separator in text files ('\\r' or '\\n' or '\\r\\n')\n",
      "      - os.defpath is the default search path for executables\n",
      "      - os.devnull is the file path of the null device ('/dev/null', etc.)\n",
      "    \n",
      "    Programs that import and use 'os' stand a better chance of being\n",
      "    portable between different platforms.  Of course, they must then\n",
      "    only use functions that are defined by all platforms (e.g., unlink\n",
      "    and opendir), and leave all pathname manipulation to os.path\n",
      "    (e.g., split and join).\n",
      "\n",
      "CLASSES\n",
      "    builtins.Exception(builtins.BaseException)\n",
      "        builtins.OSError\n",
      "    builtins.object\n",
      "        nt.DirEntry\n",
      "    builtins.tuple(builtins.object)\n",
      "        nt.times_result\n",
      "        nt.uname_result\n",
      "        stat_result\n",
      "        statvfs_result\n",
      "        terminal_size\n",
      "    \n",
      "    class DirEntry(builtins.object)\n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __fspath__(...)\n",
      "     |      returns the path for the entry\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  inode(...)\n",
      "     |      return inode of the entry; cached per entry\n",
      "     |  \n",
      "     |  is_dir(...)\n",
      "     |      return True if the entry is a directory; cached per entry\n",
      "     |  \n",
      "     |  is_file(...)\n",
      "     |      return True if the entry is a file; cached per entry\n",
      "     |  \n",
      "     |  is_symlink(...)\n",
      "     |      return True if the entry is a symbolic link; cached per entry\n",
      "     |  \n",
      "     |  stat(...)\n",
      "     |      return stat_result object for the entry; cached per entry\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  name\n",
      "     |      the entry's base filename, relative to scandir() \"path\" argument\n",
      "     |  \n",
      "     |  path\n",
      "     |      the entry's full path name; equivalent to os.path.join(scandir_path, entry.name)\n",
      "    \n",
      "    error = class OSError(Exception)\n",
      "     |  Base class for I/O related errors.\n",
      "     |  \n",
      "     |  Method resolution order:\n",
      "     |      OSError\n",
      "     |      Exception\n",
      "     |      BaseException\n",
      "     |      object\n",
      "     |  \n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __init__(self, /, *args, **kwargs)\n",
      "     |      Initialize self.  See help(type(self)) for accurate signature.\n",
      "     |  \n",
      "     |  __new__(*args, **kwargs) from builtins.type\n",
      "     |      Create and return a new object.  See help(type) for accurate signature.\n",
      "     |  \n",
      "     |  __reduce__(...)\n",
      "     |      helper for pickle\n",
      "     |  \n",
      "     |  __str__(self, /)\n",
      "     |      Return str(self).\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  characters_written\n",
      "     |  \n",
      "     |  errno\n",
      "     |      POSIX exception code\n",
      "     |  \n",
      "     |  filename\n",
      "     |      exception filename\n",
      "     |  \n",
      "     |  filename2\n",
      "     |      second exception filename\n",
      "     |  \n",
      "     |  strerror\n",
      "     |      exception strerror\n",
      "     |  \n",
      "     |  winerror\n",
      "     |      Win32 exception code\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Methods inherited from BaseException:\n",
      "     |  \n",
      "     |  __delattr__(self, name, /)\n",
      "     |      Implement delattr(self, name).\n",
      "     |  \n",
      "     |  __getattribute__(self, name, /)\n",
      "     |      Return getattr(self, name).\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  __setattr__(self, name, value, /)\n",
      "     |      Implement setattr(self, name, value).\n",
      "     |  \n",
      "     |  __setstate__(...)\n",
      "     |  \n",
      "     |  with_traceback(...)\n",
      "     |      Exception.with_traceback(tb) --\n",
      "     |      set self.__traceback__ to tb and return self.\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors inherited from BaseException:\n",
      "     |  \n",
      "     |  __cause__\n",
      "     |      exception cause\n",
      "     |  \n",
      "     |  __context__\n",
      "     |      exception context\n",
      "     |  \n",
      "     |  __dict__\n",
      "     |  \n",
      "     |  __suppress_context__\n",
      "     |  \n",
      "     |  __traceback__\n",
      "     |  \n",
      "     |  args\n",
      "    \n",
      "    class stat_result(builtins.tuple)\n",
      "     |  stat_result: Result from stat, fstat, or lstat.\n",
      "     |  \n",
      "     |  This object may be accessed either as a tuple of\n",
      "     |    (mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime)\n",
      "     |  or via the attributes st_mode, st_ino, st_dev, st_nlink, st_uid, and so on.\n",
      "     |  \n",
      "     |  Posix/windows: If your platform supports st_blksize, st_blocks, st_rdev,\n",
      "     |  or st_flags, they are available as attributes only.\n",
      "     |  \n",
      "     |  See os.stat for more information.\n",
      "     |  \n",
      "     |  Method resolution order:\n",
      "     |      stat_result\n",
      "     |      builtins.tuple\n",
      "     |      builtins.object\n",
      "     |  \n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __new__(*args, **kwargs) from builtins.type\n",
      "     |      Create and return a new object.  See help(type) for accurate signature.\n",
      "     |  \n",
      "     |  __reduce__(...)\n",
      "     |      helper for pickle\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  st_atime\n",
      "     |      time of last access\n",
      "     |  \n",
      "     |  st_atime_ns\n",
      "     |      time of last access in nanoseconds\n",
      "     |  \n",
      "     |  st_ctime\n",
      "     |      time of last change\n",
      "     |  \n",
      "     |  st_ctime_ns\n",
      "     |      time of last change in nanoseconds\n",
      "     |  \n",
      "     |  st_dev\n",
      "     |      device\n",
      "     |  \n",
      "     |  st_file_attributes\n",
      "     |      Windows file attribute bits\n",
      "     |  \n",
      "     |  st_gid\n",
      "     |      group ID of owner\n",
      "     |  \n",
      "     |  st_ino\n",
      "     |      inode\n",
      "     |  \n",
      "     |  st_mode\n",
      "     |      protection bits\n",
      "     |  \n",
      "     |  st_mtime\n",
      "     |      time of last modification\n",
      "     |  \n",
      "     |  st_mtime_ns\n",
      "     |      time of last modification in nanoseconds\n",
      "     |  \n",
      "     |  st_nlink\n",
      "     |      number of hard links\n",
      "     |  \n",
      "     |  st_size\n",
      "     |      total size, in bytes\n",
      "     |  \n",
      "     |  st_uid\n",
      "     |      user ID of owner\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data and other attributes defined here:\n",
      "     |  \n",
      "     |  n_fields = 17\n",
      "     |  \n",
      "     |  n_sequence_fields = 10\n",
      "     |  \n",
      "     |  n_unnamed_fields = 3\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Methods inherited from builtins.tuple:\n",
      "     |  \n",
      "     |  __add__(self, value, /)\n",
      "     |      Return self+value.\n",
      "     |  \n",
      "     |  __contains__(self, key, /)\n",
      "     |      Return key in self.\n",
      "     |  \n",
      "     |  __eq__(self, value, /)\n",
      "     |      Return self==value.\n",
      "     |  \n",
      "     |  __ge__(self, value, /)\n",
      "     |      Return self>=value.\n",
      "     |  \n",
      "     |  __getattribute__(self, name, /)\n",
      "     |      Return getattr(self, name).\n",
      "     |  \n",
      "     |  __getitem__(self, key, /)\n",
      "     |      Return self[key].\n",
      "     |  \n",
      "     |  __getnewargs__(...)\n",
      "     |  \n",
      "     |  __gt__(self, value, /)\n",
      "     |      Return self>value.\n",
      "     |  \n",
      "     |  __hash__(self, /)\n",
      "     |      Return hash(self).\n",
      "     |  \n",
      "     |  __iter__(self, /)\n",
      "     |      Implement iter(self).\n",
      "     |  \n",
      "     |  __le__(self, value, /)\n",
      "     |      Return self<=value.\n",
      "     |  \n",
      "     |  __len__(self, /)\n",
      "     |      Return len(self).\n",
      "     |  \n",
      "     |  __lt__(self, value, /)\n",
      "     |      Return self<value.\n",
      "     |  \n",
      "     |  __mul__(self, value, /)\n",
      "     |      Return self*value.n\n",
      "     |  \n",
      "     |  __ne__(self, value, /)\n",
      "     |      Return self!=value.\n",
      "     |  \n",
      "     |  __rmul__(self, value, /)\n",
      "     |      Return self*value.\n",
      "     |  \n",
      "     |  count(...)\n",
      "     |      T.count(value) -> integer -- return number of occurrences of value\n",
      "     |  \n",
      "     |  index(...)\n",
      "     |      T.index(value, [start, [stop]]) -> integer -- return first index of value.\n",
      "     |      Raises ValueError if the value is not present.\n",
      "    \n",
      "    class statvfs_result(builtins.tuple)\n",
      "     |  statvfs_result: Result from statvfs or fstatvfs.\n",
      "     |  \n",
      "     |  This object may be accessed either as a tuple of\n",
      "     |    (bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flag, namemax),\n",
      "     |  or via the attributes f_bsize, f_frsize, f_blocks, f_bfree, and so on.\n",
      "     |  \n",
      "     |  See os.statvfs for more information.\n",
      "     |  \n",
      "     |  Method resolution order:\n",
      "     |      statvfs_result\n",
      "     |      builtins.tuple\n",
      "     |      builtins.object\n",
      "     |  \n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __new__(*args, **kwargs) from builtins.type\n",
      "     |      Create and return a new object.  See help(type) for accurate signature.\n",
      "     |  \n",
      "     |  __reduce__(...)\n",
      "     |      helper for pickle\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  f_bavail\n",
      "     |  \n",
      "     |  f_bfree\n",
      "     |  \n",
      "     |  f_blocks\n",
      "     |  \n",
      "     |  f_bsize\n",
      "     |  \n",
      "     |  f_favail\n",
      "     |  \n",
      "     |  f_ffree\n",
      "     |  \n",
      "     |  f_files\n",
      "     |  \n",
      "     |  f_flag\n",
      "     |  \n",
      "     |  f_frsize\n",
      "     |  \n",
      "     |  f_namemax\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data and other attributes defined here:\n",
      "     |  \n",
      "     |  n_fields = 10\n",
      "     |  \n",
      "     |  n_sequence_fields = 10\n",
      "     |  \n",
      "     |  n_unnamed_fields = 0\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Methods inherited from builtins.tuple:\n",
      "     |  \n",
      "     |  __add__(self, value, /)\n",
      "     |      Return self+value.\n",
      "     |  \n",
      "     |  __contains__(self, key, /)\n",
      "     |      Return key in self.\n",
      "     |  \n",
      "     |  __eq__(self, value, /)\n",
      "     |      Return self==value.\n",
      "     |  \n",
      "     |  __ge__(self, value, /)\n",
      "     |      Return self>=value.\n",
      "     |  \n",
      "     |  __getattribute__(self, name, /)\n",
      "     |      Return getattr(self, name).\n",
      "     |  \n",
      "     |  __getitem__(self, key, /)\n",
      "     |      Return self[key].\n",
      "     |  \n",
      "     |  __getnewargs__(...)\n",
      "     |  \n",
      "     |  __gt__(self, value, /)\n",
      "     |      Return self>value.\n",
      "     |  \n",
      "     |  __hash__(self, /)\n",
      "     |      Return hash(self).\n",
      "     |  \n",
      "     |  __iter__(self, /)\n",
      "     |      Implement iter(self).\n",
      "     |  \n",
      "     |  __le__(self, value, /)\n",
      "     |      Return self<=value.\n",
      "     |  \n",
      "     |  __len__(self, /)\n",
      "     |      Return len(self).\n",
      "     |  \n",
      "     |  __lt__(self, value, /)\n",
      "     |      Return self<value.\n",
      "     |  \n",
      "     |  __mul__(self, value, /)\n",
      "     |      Return self*value.n\n",
      "     |  \n",
      "     |  __ne__(self, value, /)\n",
      "     |      Return self!=value.\n",
      "     |  \n",
      "     |  __rmul__(self, value, /)\n",
      "     |      Return self*value.\n",
      "     |  \n",
      "     |  count(...)\n",
      "     |      T.count(value) -> integer -- return number of occurrences of value\n",
      "     |  \n",
      "     |  index(...)\n",
      "     |      T.index(value, [start, [stop]]) -> integer -- return first index of value.\n",
      "     |      Raises ValueError if the value is not present.\n",
      "    \n",
      "    class terminal_size(builtins.tuple)\n",
      "     |  A tuple of (columns, lines) for holding terminal window size\n",
      "     |  \n",
      "     |  Method resolution order:\n",
      "     |      terminal_size\n",
      "     |      builtins.tuple\n",
      "     |      builtins.object\n",
      "     |  \n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __new__(*args, **kwargs) from builtins.type\n",
      "     |      Create and return a new object.  See help(type) for accurate signature.\n",
      "     |  \n",
      "     |  __reduce__(...)\n",
      "     |      helper for pickle\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  columns\n",
      "     |      width of the terminal window in characters\n",
      "     |  \n",
      "     |  lines\n",
      "     |      height of the terminal window in characters\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data and other attributes defined here:\n",
      "     |  \n",
      "     |  n_fields = 2\n",
      "     |  \n",
      "     |  n_sequence_fields = 2\n",
      "     |  \n",
      "     |  n_unnamed_fields = 0\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Methods inherited from builtins.tuple:\n",
      "     |  \n",
      "     |  __add__(self, value, /)\n",
      "     |      Return self+value.\n",
      "     |  \n",
      "     |  __contains__(self, key, /)\n",
      "     |      Return key in self.\n",
      "     |  \n",
      "     |  __eq__(self, value, /)\n",
      "     |      Return self==value.\n",
      "     |  \n",
      "     |  __ge__(self, value, /)\n",
      "     |      Return self>=value.\n",
      "     |  \n",
      "     |  __getattribute__(self, name, /)\n",
      "     |      Return getattr(self, name).\n",
      "     |  \n",
      "     |  __getitem__(self, key, /)\n",
      "     |      Return self[key].\n",
      "     |  \n",
      "     |  __getnewargs__(...)\n",
      "     |  \n",
      "     |  __gt__(self, value, /)\n",
      "     |      Return self>value.\n",
      "     |  \n",
      "     |  __hash__(self, /)\n",
      "     |      Return hash(self).\n",
      "     |  \n",
      "     |  __iter__(self, /)\n",
      "     |      Implement iter(self).\n",
      "     |  \n",
      "     |  __le__(self, value, /)\n",
      "     |      Return self<=value.\n",
      "     |  \n",
      "     |  __len__(self, /)\n",
      "     |      Return len(self).\n",
      "     |  \n",
      "     |  __lt__(self, value, /)\n",
      "     |      Return self<value.\n",
      "     |  \n",
      "     |  __mul__(self, value, /)\n",
      "     |      Return self*value.n\n",
      "     |  \n",
      "     |  __ne__(self, value, /)\n",
      "     |      Return self!=value.\n",
      "     |  \n",
      "     |  __rmul__(self, value, /)\n",
      "     |      Return self*value.\n",
      "     |  \n",
      "     |  count(...)\n",
      "     |      T.count(value) -> integer -- return number of occurrences of value\n",
      "     |  \n",
      "     |  index(...)\n",
      "     |      T.index(value, [start, [stop]]) -> integer -- return first index of value.\n",
      "     |      Raises ValueError if the value is not present.\n",
      "    \n",
      "    class times_result(builtins.tuple)\n",
      "     |  times_result: Result from os.times().\n",
      "     |  \n",
      "     |  This object may be accessed either as a tuple of\n",
      "     |    (user, system, children_user, children_system, elapsed),\n",
      "     |  or via the attributes user, system, children_user, children_system,\n",
      "     |  and elapsed.\n",
      "     |  \n",
      "     |  See os.times for more information.\n",
      "     |  \n",
      "     |  Method resolution order:\n",
      "     |      times_result\n",
      "     |      builtins.tuple\n",
      "     |      builtins.object\n",
      "     |  \n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __new__(*args, **kwargs) from builtins.type\n",
      "     |      Create and return a new object.  See help(type) for accurate signature.\n",
      "     |  \n",
      "     |  __reduce__(...)\n",
      "     |      helper for pickle\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  children_system\n",
      "     |      system time of children\n",
      "     |  \n",
      "     |  children_user\n",
      "     |      user time of children\n",
      "     |  \n",
      "     |  elapsed\n",
      "     |      elapsed time since an arbitrary point in the past\n",
      "     |  \n",
      "     |  system\n",
      "     |      system time\n",
      "     |  \n",
      "     |  user\n",
      "     |      user time\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data and other attributes defined here:\n",
      "     |  \n",
      "     |  n_fields = 5\n",
      "     |  \n",
      "     |  n_sequence_fields = 5\n",
      "     |  \n",
      "     |  n_unnamed_fields = 0\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Methods inherited from builtins.tuple:\n",
      "     |  \n",
      "     |  __add__(self, value, /)\n",
      "     |      Return self+value.\n",
      "     |  \n",
      "     |  __contains__(self, key, /)\n",
      "     |      Return key in self.\n",
      "     |  \n",
      "     |  __eq__(self, value, /)\n",
      "     |      Return self==value.\n",
      "     |  \n",
      "     |  __ge__(self, value, /)\n",
      "     |      Return self>=value.\n",
      "     |  \n",
      "     |  __getattribute__(self, name, /)\n",
      "     |      Return getattr(self, name).\n",
      "     |  \n",
      "     |  __getitem__(self, key, /)\n",
      "     |      Return self[key].\n",
      "     |  \n",
      "     |  __getnewargs__(...)\n",
      "     |  \n",
      "     |  __gt__(self, value, /)\n",
      "     |      Return self>value.\n",
      "     |  \n",
      "     |  __hash__(self, /)\n",
      "     |      Return hash(self).\n",
      "     |  \n",
      "     |  __iter__(self, /)\n",
      "     |      Implement iter(self).\n",
      "     |  \n",
      "     |  __le__(self, value, /)\n",
      "     |      Return self<=value.\n",
      "     |  \n",
      "     |  __len__(self, /)\n",
      "     |      Return len(self).\n",
      "     |  \n",
      "     |  __lt__(self, value, /)\n",
      "     |      Return self<value.\n",
      "     |  \n",
      "     |  __mul__(self, value, /)\n",
      "     |      Return self*value.n\n",
      "     |  \n",
      "     |  __ne__(self, value, /)\n",
      "     |      Return self!=value.\n",
      "     |  \n",
      "     |  __rmul__(self, value, /)\n",
      "     |      Return self*value.\n",
      "     |  \n",
      "     |  count(...)\n",
      "     |      T.count(value) -> integer -- return number of occurrences of value\n",
      "     |  \n",
      "     |  index(...)\n",
      "     |      T.index(value, [start, [stop]]) -> integer -- return first index of value.\n",
      "     |      Raises ValueError if the value is not present.\n",
      "    \n",
      "    class uname_result(builtins.tuple)\n",
      "     |  uname_result: Result from os.uname().\n",
      "     |  \n",
      "     |  This object may be accessed either as a tuple of\n",
      "     |    (sysname, nodename, release, version, machine),\n",
      "     |  or via the attributes sysname, nodename, release, version, and machine.\n",
      "     |  \n",
      "     |  See os.uname for more information.\n",
      "     |  \n",
      "     |  Method resolution order:\n",
      "     |      uname_result\n",
      "     |      builtins.tuple\n",
      "     |      builtins.object\n",
      "     |  \n",
      "     |  Methods defined here:\n",
      "     |  \n",
      "     |  __new__(*args, **kwargs) from builtins.type\n",
      "     |      Create and return a new object.  See help(type) for accurate signature.\n",
      "     |  \n",
      "     |  __reduce__(...)\n",
      "     |      helper for pickle\n",
      "     |  \n",
      "     |  __repr__(self, /)\n",
      "     |      Return repr(self).\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data descriptors defined here:\n",
      "     |  \n",
      "     |  machine\n",
      "     |      hardware identifier\n",
      "     |  \n",
      "     |  nodename\n",
      "     |      name of machine on network (implementation-defined)\n",
      "     |  \n",
      "     |  release\n",
      "     |      operating system release\n",
      "     |  \n",
      "     |  sysname\n",
      "     |      operating system name\n",
      "     |  \n",
      "     |  version\n",
      "     |      operating system version\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Data and other attributes defined here:\n",
      "     |  \n",
      "     |  n_fields = 5\n",
      "     |  \n",
      "     |  n_sequence_fields = 5\n",
      "     |  \n",
      "     |  n_unnamed_fields = 0\n",
      "     |  \n",
      "     |  ----------------------------------------------------------------------\n",
      "     |  Methods inherited from builtins.tuple:\n",
      "     |  \n",
      "     |  __add__(self, value, /)\n",
      "     |      Return self+value.\n",
      "     |  \n",
      "     |  __contains__(self, key, /)\n",
      "     |      Return key in self.\n",
      "     |  \n",
      "     |  __eq__(self, value, /)\n",
      "     |      Return self==value.\n",
      "     |  \n",
      "     |  __ge__(self, value, /)\n",
      "     |      Return self>=value.\n",
      "     |  \n",
      "     |  __getattribute__(self, name, /)\n",
      "     |      Return getattr(self, name).\n",
      "     |  \n",
      "     |  __getitem__(self, key, /)\n",
      "     |      Return self[key].\n",
      "     |  \n",
      "     |  __getnewargs__(...)\n",
      "     |  \n",
      "     |  __gt__(self, value, /)\n",
      "     |      Return self>value.\n",
      "     |  \n",
      "     |  __hash__(self, /)\n",
      "     |      Return hash(self).\n",
      "     |  \n",
      "     |  __iter__(self, /)\n",
      "     |      Implement iter(self).\n",
      "     |  \n",
      "     |  __le__(self, value, /)\n",
      "     |      Return self<=value.\n",
      "     |  \n",
      "     |  __len__(self, /)\n",
      "     |      Return len(self).\n",
      "     |  \n",
      "     |  __lt__(self, value, /)\n",
      "     |      Return self<value.\n",
      "     |  \n",
      "     |  __mul__(self, value, /)\n",
      "     |      Return self*value.n\n",
      "     |  \n",
      "     |  __ne__(self, value, /)\n",
      "     |      Return self!=value.\n",
      "     |  \n",
      "     |  __rmul__(self, value, /)\n",
      "     |      Return self*value.\n",
      "     |  \n",
      "     |  count(...)\n",
      "     |      T.count(value) -> integer -- return number of occurrences of value\n",
      "     |  \n",
      "     |  index(...)\n",
      "     |      T.index(value, [start, [stop]]) -> integer -- return first index of value.\n",
      "     |      Raises ValueError if the value is not present.\n",
      "\n",
      "FUNCTIONS\n",
      "    _exit(status)\n",
      "        Exit to the system with specified status, without normal exit processing.\n",
      "    \n",
      "    abort()\n",
      "        Abort the interpreter immediately.\n",
      "        \n",
      "        This function 'dumps core' or otherwise fails in the hardest way possible\n",
      "        on the hosting operating system.  This function never returns.\n",
      "    \n",
      "    access(path, mode, *, dir_fd=None, effective_ids=False, follow_symlinks=True)\n",
      "        Use the real uid/gid to test for access to a path.\n",
      "        \n",
      "          path\n",
      "            Path to be tested; can be string or bytes\n",
      "          mode\n",
      "            Operating-system mode bitfield.  Can be F_OK to test existence,\n",
      "            or the inclusive-OR of R_OK, W_OK, and X_OK.\n",
      "          dir_fd\n",
      "            If not None, it should be a file descriptor open to a directory,\n",
      "            and path should be relative; path will then be relative to that\n",
      "            directory.\n",
      "          effective_ids\n",
      "            If True, access will use the effective uid/gid instead of\n",
      "            the real uid/gid.\n",
      "          follow_symlinks\n",
      "            If False, and the last element of the path is a symbolic link,\n",
      "            access will examine the symbolic link itself instead of the file\n",
      "            the link points to.\n",
      "        \n",
      "        dir_fd, effective_ids, and follow_symlinks may not be implemented\n",
      "          on your platform.  If they are unavailable, using them will raise a\n",
      "          NotImplementedError.\n",
      "        \n",
      "        Note that most operations will use the effective uid/gid, therefore this\n",
      "          routine can be used in a suid/sgid environment to test if the invoking user\n",
      "          has the specified access to the path.\n",
      "    \n",
      "    chdir(path)\n",
      "        Change the current working directory to the specified path.\n",
      "        \n",
      "        path may always be specified as a string.\n",
      "        On some platforms, path may also be specified as an open file descriptor.\n",
      "          If this functionality is unavailable, using it raises an exception.\n",
      "    \n",
      "    chmod(path, mode, *, dir_fd=None, follow_symlinks=True)\n",
      "        Change the access permissions of a file.\n",
      "        \n",
      "          path\n",
      "            Path to be modified.  May always be specified as a str or bytes.\n",
      "            On some platforms, path may also be specified as an open file descriptor.\n",
      "            If this functionality is unavailable, using it raises an exception.\n",
      "          mode\n",
      "            Operating-system mode bitfield.\n",
      "          dir_fd\n",
      "            If not None, it should be a file descriptor open to a directory,\n",
      "            and path should be relative; path will then be relative to that\n",
      "            directory.\n",
      "          follow_symlinks\n",
      "            If False, and the last element of the path is a symbolic link,\n",
      "            chmod will modify the symbolic link itself instead of the file\n",
      "            the link points to.\n",
      "        \n",
      "        It is an error to use dir_fd or follow_symlinks when specifying path as\n",
      "          an open file descriptor.\n",
      "        dir_fd and follow_symlinks may not be implemented on your platform.\n",
      "          If they are unavailable, using them will raise a NotImplementedError.\n",
      "    \n",
      "    close(fd)\n",
      "        Close a file descriptor.\n",
      "    \n",
      "    closerange(fd_low, fd_high, /)\n",
      "        Closes all file descriptors in [fd_low, fd_high), ignoring errors.\n",
      "    \n",
      "    cpu_count()\n",
      "        Return the number of CPUs in the system; return None if indeterminable.\n",
      "        \n",
      "        This number is not equivalent to the number of CPUs the current process can\n",
      "        use.  The number of usable CPUs can be obtained with\n",
      "        ``len(os.sched_getaffinity(0))``\n",
      "    \n",
      "    device_encoding(fd)\n",
      "        Return a string describing the encoding of a terminal's file descriptor.\n",
      "        \n",
      "        The file descriptor must be attached to a terminal.\n",
      "        If the device is not a terminal, return None.\n",
      "    \n",
      "    dup(fd, /)\n",
      "        Return a duplicate of a file descriptor.\n",
      "    \n",
      "    dup2(fd, fd2, inheritable=True)\n",
      "        Duplicate file descriptor.\n",
      "    \n",
      "    execl(file, *args)\n",
      "        execl(file, *args)\n",
      "        \n",
      "        Execute the executable file with argument list args, replacing the\n",
      "        current process.\n",
      "    \n",
      "    execle(file, *args)\n",
      "        execle(file, *args, env)\n",
      "        \n",
      "        Execute the executable file with argument list args and\n",
      "        environment env, replacing the current process.\n",
      "    \n",
      "    execlp(file, *args)\n",
      "        execlp(file, *args)\n",
      "        \n",
      "        Execute the executable file (which is searched for along $PATH)\n",
      "        with argument list args, replacing the current process.\n",
      "    \n",
      "    execlpe(file, *args)\n",
      "        execlpe(file, *args, env)\n",
      "        \n",
      "        Execute the executable file (which is searched for along $PATH)\n",
      "        with argument list args and environment env, replacing the current\n",
      "        process.\n",
      "    \n",
      "    execv(path, argv, /)\n",
      "        Execute an executable path with arguments, replacing current process.\n",
      "        \n",
      "        path\n",
      "          Path of executable file.\n",
      "        argv\n",
      "          Tuple or list of strings.\n",
      "    \n",
      "    execve(path, argv, env)\n",
      "        Execute an executable path with arguments, replacing current process.\n",
      "        \n",
      "        path\n",
      "          Path of executable file.\n",
      "        argv\n",
      "          Tuple or list of strings.\n",
      "        env\n",
      "          Dictionary of strings mapping to strings.\n",
      "    \n",
      "    execvp(file, args)\n",
      "        execvp(file, args)\n",
      "        \n",
      "        Execute the executable file (which is searched for along $PATH)\n",
      "        with argument list args, replacing the current process.\n",
      "        args may be a list or tuple of strings.\n",
      "    \n",
      "    execvpe(file, args, env)\n",
      "        execvpe(file, args, env)\n",
      "        \n",
      "        Execute the executable file (which is searched for along $PATH)\n",
      "        with argument list args and environment env , replacing the\n",
      "        current process.\n",
      "        args may be a list or tuple of strings.\n",
      "    \n",
      "    fdopen(fd, *args, **kwargs)\n",
      "        # Supply os.fdopen()\n",
      "    \n",
      "    fsdecode(filename)\n",
      "        Decode filename (an os.PathLike, bytes, or str) from the filesystem\n",
      "        encoding with 'surrogateescape' error handler, return str unchanged. On\n",
      "        Windows, use 'strict' error handler if the file system encoding is\n",
      "        'mbcs' (which is the default encoding).\n",
      "    \n",
      "    fsencode(filename)\n",
      "        Encode filename (an os.PathLike, bytes, or str) to the filesystem\n",
      "        encoding with 'surrogateescape' error handler, return bytes unchanged.\n",
      "        On Windows, use 'strict' error handler if the file system encoding is\n",
      "        'mbcs' (which is the default encoding).\n",
      "    \n",
      "    fspath(path)\n",
      "        Return the file system path representation of the object.\n",
      "        \n",
      "        If the object is str or bytes, then allow it to pass through as-is. If the\n",
      "        object defines __fspath__(), then return the result of that method. All other\n",
      "        types raise a TypeError.\n",
      "    \n",
      "    fstat(fd)\n",
      "        Perform a stat system call on the given file descriptor.\n",
      "        \n",
      "        Like stat(), but for an open file descriptor.\n",
      "        Equivalent to os.stat(fd).\n",
      "    \n",
      "    fsync(fd)\n",
      "        Force write of fd to disk.\n",
      "    \n",
      "    ftruncate(fd, length, /)\n",
      "        Truncate a file, specified by file descriptor, to a specific length.\n",
      "    \n",
      "    get_exec_path(env=None)\n",
      "        Returns the sequence of directories that will be searched for the\n",
      "        named executable (similar to a shell) when launching a process.\n",
      "        \n",
      "        *env* must be an environment variable dict or None.  If *env* is None,\n",
      "        os.environ will be used.\n",
      "    \n",
      "    get_handle_inheritable(handle, /)\n",
      "        Get the close-on-exe flag of the specified file descriptor.\n",
      "    \n",
      "    get_inheritable(fd, /)\n",
      "        Get the close-on-exe flag of the specified file descriptor.\n",
      "    \n",
      "    get_terminal_size(...)\n",
      "        Return the size of the terminal window as (columns, lines).\n",
      "        \n",
      "        The optional argument fd (default standard output) specifies\n",
      "        which file descriptor should be queried.\n",
      "        \n",
      "        If the file descriptor is not connected to a terminal, an OSError\n",
      "        is thrown.\n",
      "        \n",
      "        This function will only be defined if an implementation is\n",
      "        available for this system.\n",
      "        \n",
      "        shutil.get_terminal_size is the high-level function which should \n",
      "        normally be used, os.get_terminal_size is the low-level implementation.\n",
      "    \n",
      "    getcwd()\n",
      "        Return a unicode string representing the current working directory.\n",
      "    \n",
      "    getcwdb()\n",
      "        Return a bytes string representing the current working directory.\n",
      "    \n",
      "    getenv(key, default=None)\n",
      "        Get an environment variable, return None if it doesn't exist.\n",
      "        The optional second argument can specify an alternate default.\n",
      "        key, default and the result are str.\n",
      "    \n",
      "    getlogin()\n",
      "        Return the actual login name.\n",
      "    \n",
      "    getpid()\n",
      "        Return the current process id.\n",
      "    \n",
      "    getppid()\n",
      "        Return the parent's process id.\n",
      "        \n",
      "        If the parent process has already exited, Windows machines will still\n",
      "        return its id; others systems will return the id of the 'init' process (1).\n",
      "    \n",
      "    isatty(fd, /)\n",
      "        Return True if the fd is connected to a terminal.\n",
      "        \n",
      "        Return True if the file descriptor is an open file descriptor\n",
      "        connected to the slave end of a terminal.\n",
      "    \n",
      "    kill(pid, signal, /)\n",
      "        Kill a process with a signal.\n",
      "    \n",
      "    link(src, dst, *, src_dir_fd=None, dst_dir_fd=None, follow_symlinks=True)\n",
      "        Create a hard link to a file.\n",
      "        \n",
      "        If either src_dir_fd or dst_dir_fd is not None, it should be a file\n",
      "          descriptor open to a directory, and the respective path string (src or dst)\n",
      "          should be relative; the path will then be relative to that directory.\n",
      "        If follow_symlinks is False, and the last element of src is a symbolic\n",
      "          link, link will create a link to the symbolic link itself instead of the\n",
      "          file the link points to.\n",
      "        src_dir_fd, dst_dir_fd, and follow_symlinks may not be implemented on your\n",
      "          platform.  If they are unavailable, using them will raise a\n",
      "          NotImplementedError.\n",
      "    \n",
      "    listdir(path=None)\n",
      "        Return a list containing the names of the files in the directory.\n",
      "        \n",
      "        path can be specified as either str or bytes.  If path is bytes,\n",
      "          the filenames returned will also be bytes; in all other circumstances\n",
      "          the filenames returned will be str.\n",
      "        If path is None, uses the path='.'.\n",
      "        On some platforms, path may also be specified as an open file descriptor;\\\n",
      "          the file descriptor must refer to a directory.\n",
      "          If this functionality is unavailable, using it raises NotImplementedError.\n",
      "        \n",
      "        The list is in arbitrary order.  It does not include the special\n",
      "        entries '.' and '..' even if they are present in the directory.\n",
      "    \n",
      "    lseek(fd, position, how, /)\n",
      "        Set the position of a file descriptor.  Return the new position.\n",
      "        \n",
      "        Return the new cursor position in number of bytes\n",
      "        relative to the beginning of the file.\n",
      "    \n",
      "    lstat(path, *, dir_fd=None)\n",
      "        Perform a stat system call on the given path, without following symbolic links.\n",
      "        \n",
      "        Like stat(), but do not follow symbolic links.\n",
      "        Equivalent to stat(path, follow_symlinks=False).\n",
      "    \n",
      "    makedirs(name, mode=511, exist_ok=False)\n",
      "        makedirs(name [, mode=0o777][, exist_ok=False])\n",
      "        \n",
      "        Super-mkdir; create a leaf directory and all intermediate ones.  Works like\n",
      "        mkdir, except that any intermediate path segment (not just the rightmost)\n",
      "        will be created if it does not exist. If the target directory already\n",
      "        exists, raise an OSError if exist_ok is False. Otherwise no exception is\n",
      "        raised.  This is recursive.\n",
      "    \n",
      "    mkdir(path, mode=511, *, dir_fd=None)\n",
      "        Create a directory.\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "        \n",
      "        The mode argument is ignored on Windows.\n",
      "    \n",
      "    open(path, flags, mode=511, *, dir_fd=None)\n",
      "        Open a file for low level IO.  Returns a file descriptor (integer).\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "    \n",
      "    pipe()\n",
      "        Create a pipe.\n",
      "        \n",
      "        Returns a tuple of two file descriptors:\n",
      "          (read_fd, write_fd)\n",
      "    \n",
      "    popen(cmd, mode='r', buffering=-1)\n",
      "        # Supply os.popen()\n",
      "    \n",
      "    putenv(name, value, /)\n",
      "        Change or add an environment variable.\n",
      "    \n",
      "    read(fd, length, /)\n",
      "        Read from a file descriptor.  Returns a bytes object.\n",
      "    \n",
      "    readlink(...)\n",
      "        readlink(path, *, dir_fd=None) -> path\n",
      "        \n",
      "        Return a string representing the path to which the symbolic link points.\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "    \n",
      "    remove(path, *, dir_fd=None)\n",
      "        Remove a file (same as unlink()).\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "    \n",
      "    removedirs(name)\n",
      "        removedirs(name)\n",
      "        \n",
      "        Super-rmdir; remove a leaf directory and all empty intermediate\n",
      "        ones.  Works like rmdir except that, if the leaf directory is\n",
      "        successfully removed, directories corresponding to rightmost path\n",
      "        segments will be pruned away until either the whole path is\n",
      "        consumed or an error occurs.  Errors during this latter phase are\n",
      "        ignored -- they generally mean that a directory was not empty.\n",
      "    \n",
      "    rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None)\n",
      "        Rename a file or directory.\n",
      "        \n",
      "        If either src_dir_fd or dst_dir_fd is not None, it should be a file\n",
      "          descriptor open to a directory, and the respective path string (src or dst)\n",
      "          should be relative; the path will then be relative to that directory.\n",
      "        src_dir_fd and dst_dir_fd, may not be implemented on your platform.\n",
      "          If they are unavailable, using them will raise a NotImplementedError.\n",
      "    \n",
      "    renames(old, new)\n",
      "        renames(old, new)\n",
      "        \n",
      "        Super-rename; create directories as necessary and delete any left\n",
      "        empty.  Works like rename, except creation of any intermediate\n",
      "        directories needed to make the new pathname good is attempted\n",
      "        first.  After the rename, directories corresponding to rightmost\n",
      "        path segments of the old name will be pruned until either the\n",
      "        whole path is consumed or a nonempty directory is found.\n",
      "        \n",
      "        Note: this function can fail with the new directory structure made\n",
      "        if you lack permissions needed to unlink the leaf directory or\n",
      "        file.\n",
      "    \n",
      "    replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None)\n",
      "        Rename a file or directory, overwriting the destination.\n",
      "        \n",
      "        If either src_dir_fd or dst_dir_fd is not None, it should be a file\n",
      "          descriptor open to a directory, and the respective path string (src or dst)\n",
      "          should be relative; the path will then be relative to that directory.\n",
      "        src_dir_fd and dst_dir_fd, may not be implemented on your platform.\n",
      "          If they are unavailable, using them will raise a NotImplementedError.\"\n",
      "    \n",
      "    rmdir(path, *, dir_fd=None)\n",
      "        Remove a directory.\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "    \n",
      "    scandir(...)\n",
      "        scandir(path='.') -> iterator of DirEntry objects for given path\n",
      "    \n",
      "    set_handle_inheritable(handle, inheritable, /)\n",
      "        Set the inheritable flag of the specified handle.\n",
      "    \n",
      "    set_inheritable(fd, inheritable, /)\n",
      "        Set the inheritable flag of the specified file descriptor.\n",
      "    \n",
      "    spawnl(mode, file, *args)\n",
      "        spawnl(mode, file, *args) -> integer\n",
      "        \n",
      "        Execute file with arguments from args in a subprocess.\n",
      "        If mode == P_NOWAIT return the pid of the process.\n",
      "        If mode == P_WAIT return the process's exit code if it exits normally;\n",
      "        otherwise return -SIG, where SIG is the signal that killed it.\n",
      "    \n",
      "    spawnle(mode, file, *args)\n",
      "        spawnle(mode, file, *args, env) -> integer\n",
      "        \n",
      "        Execute file with arguments from args in a subprocess with the\n",
      "        supplied environment.\n",
      "        If mode == P_NOWAIT return the pid of the process.\n",
      "        If mode == P_WAIT return the process's exit code if it exits normally;\n",
      "        otherwise return -SIG, where SIG is the signal that killed it.\n",
      "    \n",
      "    spawnv(mode, path, argv, /)\n",
      "        Execute the program specified by path in a new process.\n",
      "        \n",
      "        mode\n",
      "          Mode of process creation.\n",
      "        path\n",
      "          Path of executable file.\n",
      "        argv\n",
      "          Tuple or list of strings.\n",
      "    \n",
      "    spawnve(mode, path, argv, env, /)\n",
      "        Execute the program specified by path in a new process.\n",
      "        \n",
      "        mode\n",
      "          Mode of process creation.\n",
      "        path\n",
      "          Path of executable file.\n",
      "        argv\n",
      "          Tuple or list of strings.\n",
      "        env\n",
      "          Dictionary of strings mapping to strings.\n",
      "    \n",
      "    startfile(filepath, operation=None)\n",
      "        startfile(filepath [, operation])\n",
      "        \n",
      "        Start a file with its associated application.\n",
      "        \n",
      "        When \"operation\" is not specified or \"open\", this acts like\n",
      "        double-clicking the file in Explorer, or giving the file name as an\n",
      "        argument to the DOS \"start\" command: the file is opened with whatever\n",
      "        application (if any) its extension is associated.\n",
      "        When another \"operation\" is given, it specifies what should be done with\n",
      "        the file.  A typical operation is \"print\".\n",
      "        \n",
      "        startfile returns as soon as the associated application is launched.\n",
      "        There is no option to wait for the application to close, and no way\n",
      "        to retrieve the application's exit status.\n",
      "        \n",
      "        The filepath is relative to the current directory.  If you want to use\n",
      "        an absolute path, make sure the first character is not a slash (\"/\");\n",
      "        the underlying Win32 ShellExecute function doesn't work if it is.\n",
      "    \n",
      "    stat(path, *, dir_fd=None, follow_symlinks=True)\n",
      "        Perform a stat system call on the given path.\n",
      "        \n",
      "          path\n",
      "            Path to be examined; can be string, bytes, path-like object or\n",
      "            open-file-descriptor int.\n",
      "          dir_fd\n",
      "            If not None, it should be a file descriptor open to a directory,\n",
      "            and path should be a relative string; path will then be relative to\n",
      "            that directory.\n",
      "          follow_symlinks\n",
      "            If False, and the last element of the path is a symbolic link,\n",
      "            stat will examine the symbolic link itself instead of the file\n",
      "            the link points to.\n",
      "        \n",
      "        dir_fd and follow_symlinks may not be implemented\n",
      "          on your platform.  If they are unavailable, using them will raise a\n",
      "          NotImplementedError.\n",
      "        \n",
      "        It's an error to use dir_fd or follow_symlinks when specifying path as\n",
      "          an open file descriptor.\n",
      "    \n",
      "    stat_float_times(...)\n",
      "        stat_float_times([newval]) -> oldval\n",
      "        \n",
      "        Determine whether os.[lf]stat represents time stamps as float objects.\n",
      "        \n",
      "        If value is True, future calls to stat() return floats; if it is False,\n",
      "        future calls return ints.\n",
      "        If value is omitted, return the current setting.\n",
      "    \n",
      "    strerror(code, /)\n",
      "        Translate an error code to a message string.\n",
      "    \n",
      "    symlink(src, dst, target_is_directory=False, *, dir_fd=None)\n",
      "        Create a symbolic link pointing to src named dst.\n",
      "        \n",
      "        target_is_directory is required on Windows if the target is to be\n",
      "          interpreted as a directory.  (On Windows, symlink requires\n",
      "          Windows 6.0 or greater, and raises a NotImplementedError otherwise.)\n",
      "          target_is_directory is ignored on non-Windows platforms.\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "    \n",
      "    system(command)\n",
      "        Execute the command in a subshell.\n",
      "    \n",
      "    times()\n",
      "        Return a collection containing process timing information.\n",
      "        \n",
      "        The object returned behaves like a named tuple with these fields:\n",
      "          (utime, stime, cutime, cstime, elapsed_time)\n",
      "        All fields are floating point numbers.\n",
      "    \n",
      "    truncate(path, length)\n",
      "        Truncate a file, specified by path, to a specific length.\n",
      "        \n",
      "        On some platforms, path may also be specified as an open file descriptor.\n",
      "          If this functionality is unavailable, using it raises an exception.\n",
      "    \n",
      "    umask(mask, /)\n",
      "        Set the current numeric umask and return the previous umask.\n",
      "    \n",
      "    unlink(path, *, dir_fd=None)\n",
      "        Remove a file (same as remove()).\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        dir_fd may not be implemented on your platform.\n",
      "          If it is unavailable, using it will raise a NotImplementedError.\n",
      "    \n",
      "    urandom(size, /)\n",
      "        Return a bytes object containing random bytes suitable for cryptographic use.\n",
      "    \n",
      "    utime(path, times=None, *, ns=None, dir_fd=None, follow_symlinks=True)\n",
      "        Set the access and modified time of path.\n",
      "        \n",
      "        path may always be specified as a string.\n",
      "        On some platforms, path may also be specified as an open file descriptor.\n",
      "          If this functionality is unavailable, using it raises an exception.\n",
      "        \n",
      "        If times is not None, it must be a tuple (atime, mtime);\n",
      "            atime and mtime should be expressed as float seconds since the epoch.\n",
      "        If ns is specified, it must be a tuple (atime_ns, mtime_ns);\n",
      "            atime_ns and mtime_ns should be expressed as integer nanoseconds\n",
      "            since the epoch.\n",
      "        If times is None and ns is unspecified, utime uses the current time.\n",
      "        Specifying tuples for both times and ns is an error.\n",
      "        \n",
      "        If dir_fd is not None, it should be a file descriptor open to a directory,\n",
      "          and path should be relative; path will then be relative to that directory.\n",
      "        If follow_symlinks is False, and the last element of the path is a symbolic\n",
      "          link, utime will modify the symbolic link itself instead of the file the\n",
      "          link points to.\n",
      "        It is an error to use dir_fd or follow_symlinks when specifying path\n",
      "          as an open file descriptor.\n",
      "        dir_fd and follow_symlinks may not be available on your platform.\n",
      "          If they are unavailable, using them will raise a NotImplementedError.\n",
      "    \n",
      "    waitpid(pid, options, /)\n",
      "        Wait for completion of a given process.\n",
      "        \n",
      "        Returns a tuple of information regarding the process:\n",
      "            (pid, status << 8)\n",
      "        \n",
      "        The options argument is ignored on Windows.\n",
      "    \n",
      "    walk(top, topdown=True, onerror=None, followlinks=False)\n",
      "        Directory tree generator.\n",
      "        \n",
      "        For each directory in the directory tree rooted at top (including top\n",
      "        itself, but excluding '.' and '..'), yields a 3-tuple\n",
      "        \n",
      "            dirpath, dirnames, filenames\n",
      "        \n",
      "        dirpath is a string, the path to the directory.  dirnames is a list of\n",
      "        the names of the subdirectories in dirpath (excluding '.' and '..').\n",
      "        filenames is a list of the names of the non-directory files in dirpath.\n",
      "        Note that the names in the lists are just names, with no path components.\n",
      "        To get a full path (which begins with top) to a file or directory in\n",
      "        dirpath, do os.path.join(dirpath, name).\n",
      "        \n",
      "        If optional arg 'topdown' is true or not specified, the triple for a\n",
      "        directory is generated before the triples for any of its subdirectories\n",
      "        (directories are generated top down).  If topdown is false, the triple\n",
      "        for a directory is generated after the triples for all of its\n",
      "        subdirectories (directories are generated bottom up).\n",
      "        \n",
      "        When topdown is true, the caller can modify the dirnames list in-place\n",
      "        (e.g., via del or slice assignment), and walk will only recurse into the\n",
      "        subdirectories whose names remain in dirnames; this can be used to prune the\n",
      "        search, or to impose a specific order of visiting.  Modifying dirnames when\n",
      "        topdown is false is ineffective, since the directories in dirnames have\n",
      "        already been generated by the time dirnames itself is generated. No matter\n",
      "        the value of topdown, the list of subdirectories is retrieved before the\n",
      "        tuples for the directory and its subdirectories are generated.\n",
      "        \n",
      "        By default errors from the os.scandir() call are ignored.  If\n",
      "        optional arg 'onerror' is specified, it should be a function; it\n",
      "        will be called with one argument, an OSError instance.  It can\n",
      "        report the error to continue with the walk, or raise the exception\n",
      "        to abort the walk.  Note that the filename is available as the\n",
      "        filename attribute of the exception object.\n",
      "        \n",
      "        By default, os.walk does not follow symbolic links to subdirectories on\n",
      "        systems that support them.  In order to get this functionality, set the\n",
      "        optional argument 'followlinks' to true.\n",
      "        \n",
      "        Caution:  if you pass a relative pathname for top, don't change the\n",
      "        current working directory between resumptions of walk.  walk never\n",
      "        changes the current directory, and assumes that the client doesn't\n",
      "        either.\n",
      "        \n",
      "        Example:\n",
      "        \n",
      "        import os\n",
      "        from os.path import join, getsize\n",
      "        for root, dirs, files in os.walk('python/Lib/email'):\n",
      "            print(root, \"consumes\", end=\"\")\n",
      "            print(sum([getsize(join(root, name)) for name in files]), end=\"\")\n",
      "            print(\"bytes in\", len(files), \"non-directory files\")\n",
      "            if 'CVS' in dirs:\n",
      "                dirs.remove('CVS')  # don't visit CVS directories\n",
      "    \n",
      "    write(fd, data, /)\n",
      "        Write a bytes object to a file descriptor.\n",
      "\n",
      "DATA\n",
      "    F_OK = 0\n",
      "    O_APPEND = 8\n",
      "    O_BINARY = 32768\n",
      "    O_CREAT = 256\n",
      "    O_EXCL = 1024\n",
      "    O_NOINHERIT = 128\n",
      "    O_RANDOM = 16\n",
      "    O_RDONLY = 0\n",
      "    O_RDWR = 2\n",
      "    O_SEQUENTIAL = 32\n",
      "    O_SHORT_LIVED = 4096\n",
      "    O_TEMPORARY = 64\n",
      "    O_TEXT = 16384\n",
      "    O_TRUNC = 512\n",
      "    O_WRONLY = 1\n",
      "    P_DETACH = 4\n",
      "    P_NOWAIT = 1\n",
      "    P_NOWAITO = 3\n",
      "    P_OVERLAY = 2\n",
      "    P_WAIT = 0\n",
      "    R_OK = 4\n",
      "    SEEK_CUR = 1\n",
      "    SEEK_END = 2\n",
      "    SEEK_SET = 0\n",
      "    TMP_MAX = 2147483647\n",
      "    W_OK = 2\n",
      "    X_OK = 1\n",
      "    __all__ = ['altsep', 'curdir', 'pardir', 'sep', 'pathsep', 'linesep', ...\n",
      "    altsep = '/'\n",
      "    curdir = '.'\n",
      "    defpath = r'.;C:\\bin'\n",
      "    devnull = 'nul'\n",
      "    environ = environ({'ALLUSERSPROFILE': 'C:\\\\ProgramData', '...END': 'mo...\n",
      "    extsep = '.'\n",
      "    linesep = '\\r\\n'\n",
      "    name = 'nt'\n",
      "    pardir = '..'\n",
      "    pathsep = ';'\n",
      "    sep = r'\\'\n",
      "    supports_bytes_environ = False\n",
      "\n",
      "FILE\n",
      "    d:\\python36\\lib\\os.py\n",
      "\n",
      "\n"
     ]
    }
   ],
   "source": [
    "help(os)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "一个模块只会被导入一次，不管你执行了多少次import。这样可以防止导入模块被一遍又一遍地执行。\n",
    "\n",
    "当我们使用import语句的时候，Python解释器是怎样找到对应的文件的呢？\n",
    "\n",
    "这就涉及到Python的搜索路径，搜索路径是由一系列目录名组成的，Python解释器就依次从这些目录中去寻找所引入的模块。\n",
    "\n",
    "这看起来很像环境变量，事实上，也可以通过定义环境变量的方式来确定搜索路径。\n",
    "\n",
    "搜索路径是在Python编译或安装的时候确定的，安装新的库应该也会修改。搜索路径被存储在sys模块中的path变量，做一个简单的实验，在交互式解释器中，输入以下代码："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['', 'd:\\\\python36\\\\python36.zip', 'd:\\\\python36\\\\DLLs', 'd:\\\\python36\\\\lib', 'd:\\\\python36', 'd:\\\\python36\\\\lib\\\\site-packages', 'd:\\\\python36\\\\lib\\\\site-packages\\\\ner-0.1-py3.6.egg', 'd:\\\\python36\\\\lib\\\\site-packages\\\\win32', 'd:\\\\python36\\\\lib\\\\site-packages\\\\win32\\\\lib', 'd:\\\\python36\\\\lib\\\\site-packages\\\\Pythonwin', 'd:\\\\python36\\\\lib\\\\site-packages\\\\IPython\\\\extensions', 'C:\\\\Users\\\\bhe\\\\.ipython']\n"
     ]
    }
   ],
   "source": [
    "import sys\n",
    "print(sys.path)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "sys.path 输出是一个列表，其中第一项是空串''，代表当前目录（若是从一个脚本中打印出来的话，可以更清楚地看出是哪个目录），亦即我们执行python解释器的目录（对于脚本的话就是运行的脚本所在的目录）。\n",
    "\n",
    "因此若像我一样在当前目录下存在与要引入模块同名的文件，就会把要引入的模块屏蔽掉。\n",
    "\n",
    "了解了搜索路径的概念，就可以在脚本中修改sys.path来引入一些不在搜索路径中的模块。"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## from … import 语句\n",
    "Python 的 from 语句让你从模块中导入一个指定的部分到当前命名空间中，语法如下\n",
    "<br>from modname import name1[, name2[, ... nameN]]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "INFO:logutil:hello\n"
     ]
    }
   ],
   "source": [
    "from logutil import logger\n",
    "logger.info('hello')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 深入模块\n",
    "模块除了方法定义，还可以包括可执行的代码。这些代码一般用来初始化这个模块。这些代码只有在第一次被导入时才会被执行。\n",
    "\n",
    "每个模块有各自独立的符号表，在模块内部为所有的函数当作全局符号表来使用。\n",
    "\n",
    "所以，模块的作者可以放心大胆的在模块内部使用这些全局变量，而不用担心把其他用户的全局变量搞花。\n",
    "\n",
    "从另一个方面，当你确实知道你在做什么的话，你也可以通过 modname.itemname 这样的表示法来访问模块内的函数。\n",
    "\n",
    "模块是可以导入其他模块的。在一个模块（或者脚本，或者其他地方）的最前面使用 import 来导入一个模块，当然这只是一个惯例，而不是强制的。被导入的模块的名称将被放入当前操作的模块的符号表中。\n",
    "\n",
    "还有一种导入的方法，可以使用 import 直接把模块内（函数，变量的）名称导入到当前操作模块"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "# %load fibo.py\n",
    "def fib(n):    # 定义到 n 的斐波那契数列，实时打印\n",
    "    a, b = 0, 1\n",
    "    while b < n:\n",
    "        print(b, end=' ')\n",
    "        a, b = b, a+b\n",
    "    print()\n",
    " \n",
    "def fib2(n): # 返回到 n 的斐波那契数列，返回列表\n",
    "    result = []\n",
    "    a, b = 0, 1\n",
    "    while b < n:\n",
    "        result.append(b)\n",
    "        a, b = b, a+b\n",
    "    return result"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 1, 2, 3, 5, 8, 13, 21, 34]\n"
     ]
    }
   ],
   "source": [
    "from fibo import fib, fib2\n",
    "print(fib2(50))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "这种导入的方法不会把被导入的模块的名称放在当前的字符表中（所以在这个例子里面，fibo 这个名称是没有定义的）。\n",
    "\n",
    "这还有一种方法，可以一次性的把模块中的所有（函数，变量）名称都导入到当前模块的字符表"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377]\n"
     ]
    }
   ],
   "source": [
    "from fibo import *\n",
    "print(fib2(500))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "这将把所有的名字都导入进来，但是那些由单一下划线（_）开头的名字不在此例。大多数情况， Python程序员不使用这种方法，因为引入的其它来源的命名，很可能覆盖了已有的定义"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## \\_\\_name\\_\\_属性\n",
    "一个模块被另一个程序第一次引入时，其主程序将运行。如果我们想在模块被引入时，模块中的某一程序块不执行，我们可以用\\_\\_name\\_\\_属性来使该程序块仅在该模块自身运行时执行"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "import using_name"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# %load using_name.py\n",
    "\"\"\"\n",
    "@version: 0.1\n",
    "@author: Blade He\n",
    "@license: Morningstar \n",
    "@contact: blade.he@morningstar.com\n",
    "@site: \n",
    "@software: PyCharm\n",
    "@file: using_name.py\n",
    "@time: 2018/7/22 16:09\n",
    "\"\"\"\n",
    "\n",
    "\n",
    "def startjob():\n",
    "    pass\n",
    "\n",
    "\n",
    "if __name__ == '__main__':\n",
    "    print('程序自身在运行')\n",
    "else:\n",
    "    print('我来自另一模块')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "说明： 每个模块都有一个\\_\\_name\\_\\_属性，当其值是'\\_\\_main\\_\\_'时，表明该模块自身在运行，否则是被引入。\n",
    "\n",
    "说明：\\_\\_name\\_\\_ 与 \\_\\_main\\_\\_ 底下是双下划线"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## dir()函数\n",
    "内置的函数 dir() 可以找到模块内定义的所有名称。以一个字符串列表的形式返回"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'fib', 'fib2']\n"
     ]
    }
   ],
   "source": [
    "import fibo\n",
    "print(dir(fibo))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['__displayhook__', '__doc__', '__excepthook__', '__interactivehook__', '__loader__', '__name__', '__package__', '__spec__', '__stderr__', '__stdin__', '__stdout__', '_clear_type_cache', '_current_frames', '_debugmallocstats', '_enablelegacywindowsfsencoding', '_getframe', '_git', '_home', '_xoptions', 'api_version', 'argv', 'base_exec_prefix', 'base_prefix', 'builtin_module_names', 'byteorder', 'call_tracing', 'callstats', 'copyright', 'displayhook', 'dllhandle', 'dont_write_bytecode', 'exc_info', 'excepthook', 'exec_prefix', 'executable', 'exit', 'flags', 'float_info', 'float_repr_style', 'get_asyncgen_hooks', 'get_coroutine_wrapper', 'getallocatedblocks', 'getcheckinterval', 'getdefaultencoding', 'getfilesystemencodeerrors', 'getfilesystemencoding', 'getprofile', 'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval', 'gettrace', 'getwindowsversion', 'hash_info', 'hexversion', 'implementation', 'int_info', 'intern', 'is_finalizing', 'last_traceback', 'last_type', 'last_value', 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', 'path_hooks', 'path_importer_cache', 'platform', 'prefix', 'ps1', 'ps2', 'ps3', 'set_asyncgen_hooks', 'set_coroutine_wrapper', 'setcheckinterval', 'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace', 'stderr', 'stdin', 'stdout', 'thread_info', 'version', 'version_info', 'warnoptions', 'winver']\n",
      "---------This is split line-------------------\n",
      "['argv', 'byteorder', 'callstats', 'copyright', 'displayhook', 'dllhandle', 'excepthook', 'executable', 'exit', 'flags', 'getallocatedblocks', 'getcheckinterval', 'getdefaultencoding', 'getfilesystemencodeerrors', 'getfilesystemencoding', 'getprofile', 'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval', 'gettrace', 'getwindowsversion', 'hexversion', 'implementation', 'intern', 'maxsize', 'maxunicode', 'modules', 'path', 'platform', 'prefix', 'ps1', 'ps2', 'ps3', 'setcheckinterval', 'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace', 'stderr', 'stdin', 'stdout', 'version', 'warnoptions', 'winver']\n"
     ]
    }
   ],
   "source": [
    "import sys\n",
    "print(dir(sys))\n",
    "print('---------This is split line-------------------')\n",
    "print([member for member in dir(sys) if '_' not in member])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "如果没有给定参数，那么 dir() 函数会罗列出当前定义的所有名称:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['In', 'Out', '_', '__', '___', '__builtin__', '__builtins__', '__doc__', '__loader__', '__name__', '__package__', '__spec__', '_dh', '_i', '_i1', '_i2', '_ih', '_ii', '_iii', '_oh', 'a', 'exit', 'fib', 'fibo', 'get_ipython', 'quit']\n"
     ]
    }
   ],
   "source": [
    "a = [1, 2, 3, 4, 5]\n",
    "import fibo\n",
    "fib = fibo.fib\n",
    "print(dir())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 标准模块\n",
    "Python 本身带着一些标准的模块库，在 Python 库参考文档中将会介绍到（就是后面的\"库参考文档\"）。\n",
    "\n",
    "有些模块直接被构建在解析器里，这些虽然不是一些语言内置的功能，但是他却能很高效的使用，甚至是系统级调用也没问题。\n",
    "\n",
    "这些组件会根据不同的操作系统进行不同形式的配置，比如 winreg 这个模块就只会提供给 Windows 系统。\n",
    "\n",
    "应该注意到这有一个特别的模块 sys ，它内置在每一个 Python 解析器中。变量 sys.ps1 和 sys.ps2 定义了主提示符和副提示符所对应的字符串:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "In : \n",
      "...: \n",
      "C> \n"
     ]
    }
   ],
   "source": [
    "import sys\n",
    "print(sys.ps1)\n",
    "print(sys.ps2)\n",
    "sys.ps1 = 'C> '\n",
    "print(sys.ps1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 包\n",
    "包是一种管理 Python 模块命名空间的形式，采用\"点模块名称\"。\n",
    "\n",
    "比如一个模块的名称是 A.B， 那么他表示一个包 A中的子模块 B 。\n",
    "\n",
    "就好像使用模块的时候，你不用担心不同模块之间的全局变量相互影响一样，采用点模块名称这种形式也不用担心不同库之间的模块重名的情况。\n",
    "\n",
    "这样不同的作者都可以提供 NumPy 模块，或者是 Python 图形库。\n",
    "\n",
    "不妨假设你想设计一套统一处理声音文件和数据的模块（或者称之为一个\"包\"）。\n",
    "\n",
    "现存很多种不同的音频文件格式（基本上都是通过后缀名区分的，例如： .wav，:file:.aiff，:file:.au，），所以你需要有一组不断增加的模块，用来在不同的格式之间转换。\n",
    "\n",
    "并且针对这些音频数据，还有很多不同的操作（比如混音，添加回声，增加均衡器功能，创建人造立体声效果），所以你还需要一组怎么也写不完的模块来处理这些操作。\n",
    "\n",
    "这里给出了一种可能的包结构（在分层的文件系统中）"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "```\n",
    "sound/                          顶层包\n",
    "      __init__.py               初始化 sound 包\n",
    "      formats/                  文件格式转换子包\n",
    "              __init__.py\n",
    "              wavread.py\n",
    "              wavwrite.py\n",
    "              aiffread.py\n",
    "              aiffwrite.py\n",
    "              auread.py\n",
    "              auwrite.py\n",
    "              ...\n",
    "      effects/                  声音效果子包\n",
    "              __init__.py\n",
    "              echo.py\n",
    "              surround.py\n",
    "              reverse.py\n",
    "              ...\n",
    "      filters/                  filters 子包\n",
    "              __init__.py\n",
    "              equalizer.py\n",
    "              vocoder.py\n",
    "              karaoke.py\n",
    "              ...\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "在导入一个包的时候，Python 会根据 sys.path 中的目录来寻找这个包中包含的子目录。\n",
    "\n",
    "目录只有包含一个叫做 \\_\\_init\\_\\_.py 的文件才会被认作是一个包，主要是为了避免一些滥俗的名字（比如叫做 string）不小心的影响搜索路径中的有效模块。\n",
    "\n",
    "最简单的情况，放一个空的 :file:\\_\\_init\\_\\_.py就可以了。当然这个文件中也可以包含一些初始化代码或者为（将在后面介绍的） \\_\\_all\\_\\_变量赋值。\n",
    "\n",
    "用户可以每次只导入一个包里面的特定模块，比如:"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "```\n",
    "import sound.effects.echo\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "这将会导入子模块:sound.effects.echo。 他必须使用全名去访问:"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "```\n",
    "sound.effects.echo.echofilter(input, output, delay=0.7, atten=4)\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "还有一种导入子模块的方法是:"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "```\n",
    "from sound.effects import echo\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "这同样会导入子模块: echo，并且他不需要那些冗长的前缀，所以他可以这样使用:"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "```\n",
    "echo.echofilter(input, output, delay=0.7, atten=4)\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "还有一种变化就是直接导入一个函数或者变量:"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "```\n",
    "from sound.effects.echo import echofilter\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "同样的，这种方法会导入子模块: echo，并且可以直接使用他的 echofilter() 函数:\n",
    "\n",
    "echofilter(input, output, delay=0.7, atten=4)\n",
    "\n",
    "注意当使用from package import item这种形式的时候，对应的item既可以是包里面的子模块（子包），或者包里面定义的其他名称，比如函数，类或者变量。\n",
    "\n",
    "import语法会首先把item当作一个包定义的名称，如果没找到，再试图按照一个模块去导入。如果还没找到，恭喜，一个:exc:ImportError 异常被抛出了。\n",
    "\n",
    "反之，如果使用形如import item.subitem.subsubitem这种导入形式，除了最后一项，都必须是包，而最后一项则可以是模块或者是包，但是不可以是类，函数或者变量的名字。"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "通常我们并不主张使用\\*这种方法来导入模块，因为这种方法经常会导致代码的可读性降低。不过这样倒的确是可以省去不少敲键的功夫，而且一些模块都设计成了只能通过特定的方法导入。\n",
    "\n",
    "记住，使用from Package import specific_submodule这种方法永远不会有错。事实上，这也是推荐的方法。除非是你要导入的子模块有可能和其他包的子模块重名。\n",
    "\n",
    "如果在结构中包是一个子包（比如这个例子中对于包sound来说），而你又想导入兄弟包（同级别的包）你就得使用导入绝对的路径来导入。比如，如果模块sound.filters.vocoder 要使用包sound.effects中的模块echo，你就要写成 from sound.effects import echo。"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "无论是隐式的还是显式的相对导入都是从当前模块开始的。主模块的名字永远是\"\\_\\_main\\_\\_\"，一个Python应用程序的主模块，应当总是使用绝对路径引用。\n",
    "\n",
    "包还提供一个额外的属性\\_\\_path\\_\\_。这是一个目录列表，里面每一个包含的目录都有为这个包服务的\\_\\_init\\_\\_.py，你得在其他\\_\\_init\\_\\_.py被执行前定义。可以修改这个变量，用来影响包含在包里面的模块和子包。\n",
    "\n",
    "这个功能并不常用，一般用来扩展包里面的模块"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 安装第三方包"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "一般来说，通过pip就可以安装大部分所需的python开发包，通过Windows安装的python，一般都会自带pip程序，在linux下，或许需要自行下载及安装pip"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Linux，以ubuntu为例，安装pip\n",
    "```\n",
    "sudo wget https://pypi.python.org/packages/41/80/268fda78a53c2629128f8174d2952c7f902c93ebaa2062b64f27aa101b07/setuptools-38.2.3.zip#md5=0ae64455d276ff864b40aca9c06ea7c1\n",
    "sudo unzip setuptools-38.2.3.zip\n",
    "cd setuptools-38.2.3\n",
    "sudo python setup.py install\n",
    "\n",
    "sudo wget https://pypi.python.org/packages/11/b6/abcb525026a4be042b486df43905d6893fb04f05aac21c32c638e939e447/pip-9.0.1.tar.gz#md5=35f01da33009719497f01a4ba69d63c9\n",
    "sudo tar xf pip-9.0.1.tar.gz\n",
    "cd pip-9.0.1\n",
    "sudo python setup.py install\n",
    "```\n",
    "之后，输入pip -v，应该会显示pip的版本以及对应的python信息，如：\n",
    "pip 9.0.1 from /usr/local/lib/python3.6/dist-packages/pip-9.0.1-py3.6.egg (python 3.6)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "之后，如果需要使用什么python包，就参照官方说明，直接pip install即可"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Windows系统下如果安装一些python包，出现了错误，可以直接去https://www.lfd.uci.edu/~gohlke/pythonlibs/ 下载whl文件，不过需要了解是要下载32位还是64位版本的"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "如：numpy‑1.15.0+mkl‑cp36‑cp36m‑win_amd64.whl，表示是python3.6版本，并且是64位的安装包。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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