playground_01_variables
Number data types store numeric values. They are immutable data types, means that changing the value of a number data type results in a newly allocated object.
# assigning 3 to an integer variable
anInt = 3
alsoAnInt = int(3.0)
yetAnotherInt = int("3")
# assigning 3 to a float variable
aFloat = 3.0
alsoAFloat = float(3)
# assigning 3 to a (int) and 4.1 to b (float)
a, b = 3, 4.1
# division operator always returns floats (unlike C or C++)
print(a / b) # 0.7317073170731708
# floor division
print(a // b) # 0.0
# 4.1 to the 3rd power
print(b**a) # 68.9209999
# python has in-built complex numbers :D
unicorn = 1 + 2j
# print real part of complex number
print(unicorn.real) # 1.0
# print imaginary part of complex number
print(unicorn.imag) # 2.0
# most built-in operators support complex numbersStrings are amongst the most popular types in Python. We can create them simply by enclosing characters in quotes. Python treats single quotes the same as double quotes. Creating strings is as simple as assigning a value to a variable.
# assigning to a string variable
aChar = "3" # this is actually just a one character long string
aString = "333333"
alsoAString = '3333333'
anotherString = str(3333333)
anotherString = str('3333333')
# normal string
normalString = "C:\numbers" # treats backslashes as special charaters
# raw strings (notice the r before the string)
rawString = r"C:\numbers" # ignores backslashes
# multiline strings
tripleQuotedString = """\
This kind of string can span multiple
lines
and keeps its
formatting!
"""
coolString = "The quick brown fox jumped over the lazy dog"
# get string length (number of characters)
length = len(coolString) # 44
# python slices use [start:stop:step] [-startBackwards]
index0 = coolString[0] # the letter 'T'
index5 = coolString[5] # the letter 'u'
lastChar = coolString[len(coolString) - 1] # the letter 'd'
alsoLastChar = coolString[-1] # the letter 'd'
secondToLastChar = coolString[-2] # the letter 'o'
firstChar = coolString[-len(coolString)] # the letter 'T'
coolSlice = coolString[4:23] # the string 'quick brown fox jum'
coolSliceFromStart = coolString[:23] # the string 'The quick brown fox jum'
coolSliceToEnd = coolString[4:] # 'quick brown fox jumped over the lazy dog'
pointlessSlice = coolString[::] # the original string
jumpingSlice = coolString[4:23:2] # 'qikbonfxjm'
gnirtSlooc = coolString[::-1] # reversed version of original string
# negative steps need to on an extra slicing operation
gnirtSloocSlice = coolString[0:23][::-2]
#concatenation of strings
pp = "pen pineapple"
ap = "apple pen"
concatenation = pp + ap #pen pineapple apple pen
repeatedString = "3" * 3 # string '333'
mixedTypeConcatenation = str(3) + "3" # string '33'
# can't do the following because strings in python are immutable
# coolString[0] = "l"
# though you can just as easily create a new string
newString = "l" + coolString[1:]
Find The D
