Do not shadow submodules

using object that have the same name as submodules as the weird effect
of makeing `import pip.commands.<something> as <anothername>` fail with
a key error. This fixes it by renamin commands as command_dict and fixin
a few imports to accomodate.

Related to #2149

docs/pipext.py

@@ -6,7 +6,7 @@ from docutils import nodes
 from docutils.parsers import rst
 from docutils.statemachine import ViewList
 from textwrap import dedent
-from pip import commands
+from pip.commands import commands_dict as commands
 from pip import cmdoptions
 from pip.utils import get_prog
 

pip/__init__.py

@@ -14,7 +14,11 @@ from pip.utils import get_installed_distributions, get_prog
 from pip.utils import deprecation
 from pip.vcs import git, mercurial, subversion, bazaar  # noqa
 from pip.baseparser import ConfigOptionParser, UpdatingDefaultsHelpFormatter
-from pip.commands import commands, get_summaries, get_similar_commands
+from pip.commands import get_summaries, get_similar_commands
+from pip.commands import commands_dict
+
+
+# assignment for flake8 to be happy
 
 # This fixes a peculiarity when importing via __import__ - as we are
 # initialising the pip module, "from pip import cmdoptions" is recursive
@@ -72,7 +76,7 @@ def autocomplete():
                     print(dist)
                 sys.exit(1)
 
-        subcommand = commands[subcommand_name]()
+        subcommand = commands_dict[subcommand_name]()
         options += [(opt.get_opt_string(), opt.nargs)
                     for opt in subcommand.parser.option_list_all
                     if opt.help != optparse.SUPPRESS_HELP]
@@ -158,7 +162,7 @@ def parseopts(args):
     # the subcommand name
     cmd_name = args_else[0]
 
-    if cmd_name not in commands:
+    if cmd_name not in commands_dict:
         guess = get_similar_commands(cmd_name)
 
         msg = ['unknown command "%s"' % cmd_name]
@@ -203,7 +207,7 @@ def main(args=None):
         sys.stderr.write(os.linesep)
         sys.exit(1)
 
-    command = commands[cmd_name](isolated=check_isolated(cmd_args))
+    command = commands_dict[cmd_name](isolated=check_isolated(cmd_args))
     return command.main(cmd_args)
 
 

pip/commands/__init__.py

@@ -16,7 +16,7 @@ from pip.commands.zip import ZipCommand
 from pip.commands.wheel import WheelCommand
 
 
-commands = {
+commands_dict = {
     CompletionCommand.name: CompletionCommand,
     FreezeCommand.name: FreezeCommand,
     HelpCommand.name: HelpCommand,
@@ -49,9 +49,9 @@ def get_summaries(ignore_hidden=True, ordered=True):
     """Yields sorted (command name, command summary) tuples."""
 
     if ordered:
-        cmditems = _sort_commands(commands, commands_order)
+        cmditems = _sort_commands(commands_dict, commands_order)
     else:
-        cmditems = commands.items()
+        cmditems = commands_dict.items()
 
     for name, command_class in cmditems:
         if ignore_hidden and command_class.hidden:
@@ -66,7 +66,7 @@ def get_similar_commands(name):
 
     name = name.lower()
 
-    close_commands = get_close_matches(name, commands.keys())
+    close_commands = get_close_matches(name, commands_dict.keys())
 
     if close_commands:
         return close_commands[0]

pip/commands/help.py

@@ -12,7 +12,7 @@ class HelpCommand(Command):
     summary = 'Show help for commands.'
 
     def run(self, options, args):
-        from pip.commands import commands, get_similar_commands
+        from pip.commands import commands_dict, get_similar_commands
 
         try:
             # 'pip help' with no args is handled by pip.__init__.parseopt()
@@ -20,7 +20,7 @@ class HelpCommand(Command):
         except IndexError:
             return SUCCESS
 
-        if cmd_name not in commands:
+        if cmd_name not in commands_dict:
             guess = get_similar_commands(cmd_name)
 
             msg = ['unknown command "%s"' % cmd_name]
@@ -29,7 +29,7 @@ class HelpCommand(Command):
 
             raise CommandError(' - '.join(msg))
 
-        command = commands[cmd_name]()
+        command = commands_dict[cmd_name]()
         command.parser.print_help()
 
         return SUCCESS

tests/functional/test_help.py

@@ -3,7 +3,7 @@ import pytest
 from pip.exceptions import CommandError
 from pip.basecommand import ERROR, SUCCESS
 from pip.commands.help import HelpCommand
-from pip.commands import commands
+from pip.commands import commands_dict as commands
 from mock import Mock
 
 

tests/lib/test_lib.py

@@ -52,3 +52,11 @@ def test_correct_pip_version(script):
         'mismatched source files in %r and %r: %r' %
         (pip_folder, pip_folder_outputed, mismatch_py)
     )
+
+
+def test_as_import(script):
+    """ test that pip.__init__.py does not shadow
+    the command submodule with a dictionary
+    """
+    import pip.commands.install as inst
+    assert inst is not None

tests/unit/test_options.py

@@ -4,7 +4,7 @@ import pip.baseparser
 from pip import main
 from pip import cmdoptions
 from pip.basecommand import Command
-from pip.commands import commands
+from pip.commands import commands_dict as commands
 
 
 class FakeCommand(Command):