scuba: Omit explicit string format field numbering

scuba/__main__.py

@@ -138,23 +138,23 @@ def prepare(self):
     def __str__(self):
         s = StringIO()
         writeln(s, 'ScubaDive')
-        writeln(s, '   verbose:      {0}'.format(self.verbose))
-        writeln(s, '   as_root:      {0}'.format(self.as_root))
-        writeln(s, '   workdir:      {0}'.format(self.workdir))
+        writeln(s, '   verbose:      {}'.format(self.verbose))
+        writeln(s, '   as_root:      {}'.format(self.as_root))
+        writeln(s, '   workdir:      {}'.format(self.workdir))
 
         writeln(s, '   options:')
         for a in self.options:
             writeln(s, '      ' + a)
 
         writeln(s, '   env_vars:')
         for k,v in self.env_vars.items():
-            writeln(s, '      {0}={1}'.format(k, v))
+            writeln(s, '      {}={}'.format(k, v))
 
         writeln(s, '   volumes:')
         for hostpath, contpath, options in self.__get_vol_opts():
-            writeln(s, '      {0} => {1} {2}'.format(hostpath, contpath, options))
+            writeln(s, '      {} => {} {}'.format(hostpath, contpath, options))
 
-        writeln(s, '   user_command: {0}'.format(self.user_command))
+        writeln(s, '   user_command: {}'.format(self.user_command))
         writeln(s, '   context:')
         writeln(s, '     script: ' + str(self.context.script)) 
         writeln(s, '     image:  ' + str(self.context.image)) 
@@ -199,7 +199,7 @@ def __locate_scubainit(self):
 
         self.scubainit_path = os.path.join(pkg_path, 'scubainit')
         if not os.path.isfile(self.scubainit_path):
-            raise ScubaError('scubainit not found at "{0}"'.format(self.scubainit_path))
+            raise ScubaError('scubainit not found at "{}"'.format(self.scubainit_path))
 
 
     def __load_config(self):
@@ -244,7 +244,7 @@ def __setup_native_run(self):
 
 
         # Pass variables to scubainit
-        self.add_env('SCUBAINIT_UMASK', '{0:04o}'.format(get_umask()))
+        self.add_env('SCUBAINIT_UMASK', '{:04o}'.format(get_umask()))
 
         if not self.as_root:
             self.add_env('SCUBAINIT_UID', os.getuid())
@@ -288,13 +288,13 @@ def __setup_native_run(self):
             default_cmd = get_image_command(context.image)
             if not default_cmd:
                 raise ScubaError('No command given and no image-specified command')
-            verbose_msg('{0} Cmd: "{1}"'.format(context.image, default_cmd))
+            verbose_msg('{} Cmd: "{}"'.format(context.image, default_cmd))
             context.script = [shell_quote_cmd(default_cmd)]
 
         # Make scubainit the entrypoint, and manually insert an existing
         # entrypoint before each user command
         entrypoint = get_image_entrypoint(context.image) or []
-        self.add_option('--entrypoint={0}'.format(scubainit_cpath))
+        self.add_option('--entrypoint={}'.format(scubainit_cpath))
 
         # The user command is executed via a generated shell script
         with self.open_scubadir_file('command.sh', 'wt') as f:
@@ -346,9 +346,9 @@ def __generate_hook_script(self, name):
             return
 
         # Generate the hook script, mount it into the container, and tell scubainit
-        with self.open_scubadir_file('hooks/{0}.sh'.format(name), 'wt') as f:
+        with self.open_scubadir_file('hooks/{}.sh'.format(name), 'wt') as f:
 
-            self.add_env('SCUBAINIT_HOOK_{0}'.format(name.upper()), f.container_path)
+            self.add_env('SCUBAINIT_HOOK_{}'.format(name.upper()), f.container_path)
 
             writeln(f, '#!/bin/sh')
             writeln(f, '# Auto-generated from .scuba.yml')
@@ -370,7 +370,7 @@ def get_docker_cmdline(self):
         ]
 
         for name,val in self.env_vars.items():
-            args.append('--env={0}={1}'.format(name, val))
+            args.append('--env={}={}'.format(name, val))
 
         for hostpath, contpath, options in self.__get_vol_opts():
             args.append(make_vol_opt(hostpath, contpath, options))
@@ -403,7 +403,7 @@ def run_scuba(scuba_args):
         print('ALIAS\tIMAGE')
         for name in sorted(dive.config.aliases):
             alias = dive.config.aliases[name]
-            print('{0}\t{1}'.format(alias.name, alias.image or dive.config.image))
+            print('{}\t{}'.format(alias.name, alias.image or dive.config.image))
         return
 
     try:

scuba/config.py

@@ -65,7 +65,7 @@ def from_yaml(self, node):
             for k in key.split('.'):
                 cur = cur[k]
         except KeyError:
-            raise yaml.YAMLError('Key "{0}" not found in {1}'.format(key, filename))
+            raise yaml.YAMLError('Key "{}" not found in {}'.format(key, filename))
         return cur
 
 Loader.add_constructor('!from_yaml', Loader.from_yaml)
@@ -88,14 +88,14 @@ def find_config():
             return path, rel
 
         if not cross_fs and os.path.ismount(path):
-            msg = '{0} not found here or any parent up to mount point {1}'.format(SCUBA_YML, path) \
+            msg = '{} not found here or any parent up to mount point {}'.format(SCUBA_YML, path) \
                    + '\nStopping at filesystem boundary (SCUBA_DISCOVERY_ACROSS_FILESYSTEM not set).'
             raise ConfigNotFoundError(msg)
 
         # Traverse up directory hierarchy
         path, rest = os.path.split(path)
         if not rest:
-            raise ConfigNotFoundError('{0} not found here or any parent directories'.format(SCUBA_YML))
+            raise ConfigNotFoundError('{} not found here or any parent directories'.format(SCUBA_YML))
 
         # Accumulate the relative path back to where we started
         rel = os.path.join(rest, rel)
@@ -116,17 +116,17 @@ def _process_script_node(node, name):
         # There must be a "script" key, which must be a list of strings
         script = node.get('script')
         if not script:
-            raise ConfigError("{0}: must have a 'script' subkey".format(name))
+            raise ConfigError("{}: must have a 'script' subkey".format(name))
 
         if isinstance(script, list):
             return script
 
         if isinstance(script, basestring):
             return [script]
 
-        raise ConfigError("{0}.script: must be a string or list".format(name))
+        raise ConfigError("{}.script: must be a string or list".format(name))
 
-    raise ConfigError("{0}: must be string or dict".format(name))
+    raise ConfigError("{}: must be string or dict".format(name))
 
 
 def _process_environment(node, name):
@@ -146,7 +146,7 @@ def _process_environment(node, name):
             k, v = parse_env_var(e)
             result[k] = v
     else:
-        raise ConfigError("'{0}' must be list or mapping, not {1}".format(
+        raise ConfigError("'{}' must be list or mapping, not {}".format(
                 name, type(node).__name__))
 
     return result
@@ -170,7 +170,7 @@ def from_dict(cls, name, node):
             image = node.get('image')
             environment = _process_environment(
                     node.get('environment'),
-                    '{0}.{1}'.format(name, 'environment'))
+                    '{}.{}'.format(name, 'environment'))
 
         return cls(name, script, image, environment)
 
@@ -185,13 +185,13 @@ def __init__(self, **data):
         # Check for missing required nodes
         missing = [n for n in required_nodes if not n in data]
         if missing:
-            raise ConfigError('{0}: Required node{1} missing: {2}'.format(SCUBA_YML,
+            raise ConfigError('{}: Required node{} missing: {}'.format(SCUBA_YML,
                     's' if len(missing) > 1 else '', ', '.join(missing)))
 
         # Check for unrecognized nodes
         extra = [n for n in data if not n in required_nodes + optional_nodes]
         if extra:
-            raise ConfigError('{0}: Unrecognized node{1}: {2}'.format(SCUBA_YML,
+            raise ConfigError('{}: Unrecognized node{}: {}'.format(SCUBA_YML,
                     's' if len(extra) > 1 else '', ', '.join(extra)))
 
         self._image = data['image']
@@ -293,8 +293,8 @@ def load_config(path):
         with open(path) as f:
             data = yaml.load(f, Loader)
     except IOError as e:
-        raise ConfigError('Error opening {0}: {1}'.format(SCUBA_YML, e))
+        raise ConfigError('Error opening {}: {}'.format(SCUBA_YML, e))
     except yaml.YAMLError as e:
-        raise ConfigError('Error loading {0}: {1}'.format(SCUBA_YML, e))
+        raise ConfigError('Error loading {}: {}'.format(SCUBA_YML, e))
 
     return ScubaConfig(**(data or {}))

scuba/dockerutil.py

@@ -13,7 +13,7 @@ def __init__(self, image):
         self.image = image
 
     def __str__(self):
-        return 'No such image: {0}'.format(self.image)
+        return 'No such image: {}'.format(self.image)
 
 
 def __wrap_docker_exec(func):
@@ -46,7 +46,7 @@ def docker_inspect(image):
     if not p.returncode == 0:
         if 'no such image' in stderr.lower():
             raise NoSuchImageError(image)
-        raise DockerError('Failed to inspect image: {0}'.format(stderr.strip()))
+        raise DockerError('Failed to inspect image: {}'.format(stderr.strip()))
 
     return json.loads(stdout)[0]
 
@@ -57,7 +57,7 @@ def docker_pull(image):
     # If this fails, the default docker stdout/stderr looks good to the user.
     ret = call(args)
     if ret != 0:
-        raise DockerError('Failed to pull image "{0}"'.format(image))
+        raise DockerError('Failed to pull image "{}"'.format(image))
 
 def docker_inspect_or_pull(image):
     '''Inspects a docker image, pulling it if it doesn't exist'''
@@ -74,20 +74,20 @@ def get_image_command(image):
     try:
         return info['Config']['Cmd']
     except KeyError as ke:
-        raise DockerError('Failed to inspect image: JSON result missing key {0}'.format(ke))
+        raise DockerError('Failed to inspect image: JSON result missing key {}'.format(ke))
 
 def get_image_entrypoint(image):
     '''Gets the image entrypoint'''
     info = docker_inspect_or_pull(image)
     try:
         return info['Config']['Entrypoint']
     except KeyError as ke:
-        raise DockerError('Failed to inspect image: JSON result missing key {0}'.format(ke))
+        raise DockerError('Failed to inspect image: JSON result missing key {}'.format(ke))
 
 
 def make_vol_opt(hostdir, contdir, options=None):
     '''Generate a docker volume option'''
-    vol = '--volume={0}:{1}'.format(hostdir, contdir)
+    vol = '--volume={}:{}'.format(hostdir, contdir)
     if options != None:
         if isinstance(options, str):
             options = (options,)

scuba/version.py

@@ -48,13 +48,13 @@ def get_version():
         if commits == 0 and not rev.endswith('dirty'):
             return BASE_VERSION
 
-        return '{0}+{1}-{2}'.format(BASE_VERSION, commits, rev)
+        return '{}+{}-{}'.format(BASE_VERSION, commits, rev)
 
 
     # Git archive
     # If this was produced via `git archive`, we'll use the version it provides
     if not git_archive_rev.startswith('$'):
-        return '{0}+g{1}'.format(BASE_VERSION, git_archive_rev)
+        return '{}+g{}'.format(BASE_VERSION, git_archive_rev)
 
 
     # Package resource

setup.py

@@ -41,7 +41,7 @@ def get_version():
     build_num = os.getenv('TRAVIS_BUILD_NUMBER')
     build_tag = os.getenv('TRAVIS_TAG')
     if (not build_tag) and (build_num != None):
-        return '{0}.{1}'.format(scuba.version.BASE_VERSION, build_num)
+        return '{}.{}'.format(scuba.version.BASE_VERSION, build_num)
 
     return scuba.version.__version__