Add --all option to pip freeze

In order to include pip/setuptools/wheel in the freeze output
Closes #1610

CHANGES.txt

@@ -17,6 +17,9 @@
 * Fix PipDeprecationWarning so that warnings can be turned off by
   ``-W`` / ``PYTHONWARNINGS`` (:pull:`3455`)
 
+* Add a `--all` option to `pip freeze` to include usually skipped package
+  (like pip, setuptools and wheel) to the freeze output. :issue:`1610`.
+
 
 **8.0.2 (2016-01-21)**
 

pip/commands/freeze.py

@@ -3,11 +3,15 @@ from __future__ import absolute_import
 import sys
 
 import pip
+from pip.compat import stdlib_pkgs
 from pip.basecommand import Command
 from pip.operations.freeze import freeze
 from pip.wheel import WheelCache
 
 
+DEV_PKGS = ('pip', 'setuptools', 'distribute', 'wheel')
+
+
 class FreezeCommand(Command):
     """
     Output installed packages in requirements format.
@@ -52,12 +56,22 @@ class FreezeCommand(Command):
             action='store_true',
             default=False,
             help='Only output packages installed in user-site.')
+        self.cmd_opts.add_option(
+            '--all',
+            dest='freeze_all',
+            action='store_true',
+            help='Do not skip these packages in the output:'
+                 ' %s' % ', '.join(DEV_PKGS))
 
         self.parser.insert_option_group(0, self.cmd_opts)
 
     def run(self, options, args):
         format_control = pip.index.FormatControl(set(), set())
         wheel_cache = WheelCache(options.cache_dir, format_control)
+        skip = set(stdlib_pkgs)
+        if not options.freeze_all:
+            skip.update(DEV_PKGS)
+
         freeze_kwargs = dict(
             requirement=options.requirement,
             find_links=options.find_links,
@@ -65,7 +79,8 @@ class FreezeCommand(Command):
             user_only=options.user,
             skip_regex=options.skip_requirements_regex,
             isolated=options.isolated_mode,
-            wheel_cache=wheel_cache)
+            wheel_cache=wheel_cache,
+            skip=skip)
 
         for line in freeze(**freeze_kwargs):
             sys.stdout.write(line + '\n')

pip/operations/freeze.py

@@ -4,23 +4,21 @@ import logging
 import re
 
 import pip
-from pip.compat import stdlib_pkgs
 from pip.req import InstallRequirement
-from pip.utils import get_installed_distributions
+from pip.utils import canonicalize_name, get_installed_distributions
 from pip._vendor import pkg_resources
 
 
 logger = logging.getLogger(__name__)
 
-freeze_excludes = stdlib_pkgs + ('setuptools', 'pip', 'distribute', 'wheel')
-
 
 def freeze(
         requirement=None,
         find_links=None, local_only=None, user_only=None, skip_regex=None,
         default_vcs=None,
         isolated=False,
-        wheel_cache=None):
+        wheel_cache=None,
+        skip=()):
     find_links = find_links or []
     skip_match = None
 
@@ -41,7 +39,7 @@ def freeze(
         yield '-f %s' % link
     installations = {}
     for dist in get_installed_distributions(local_only=local_only,
-                                            skip=freeze_excludes,
+                                            skip=(),
                                             user_only=user_only):
         req = pip.FrozenRequirement.from_dist(
             dist,
@@ -111,4 +109,5 @@ def freeze(
         )
     for installation in sorted(
             installations.values(), key=lambda x: x.name.lower()):
-        yield str(installation).rstrip()
+        if canonicalize_name(installation.name) not in skip:
+            yield str(installation).rstrip()

tests/functional/test_freeze.py

@@ -63,6 +63,12 @@ def test_freeze_basic(script):
     _check_output(result.stdout, expected)
 
 
+def test_freeze_with_pip(script):
+    """Test pip shows itself"""
+    result = script.pip('freeze', '--all')
+    assert 'pip==' in result.stdout
+
+
 @pytest.mark.svn
 def test_freeze_svn(script, tmpdir):
     """Test freezing a svn checkout"""

tests/unit/test_utils.py

@@ -16,7 +16,6 @@ from pip.exceptions import HashMismatch, HashMissing, InstallationError
 from pip.utils import (egg_link_path, get_installed_distributions,
                        untar_file, unzip_file, rmtree, normalize_path)
 from pip.utils.hashes import Hashes, MissingHashes
-from pip.operations.freeze import freeze_excludes
 from pip._vendor.six import BytesIO
 
 
@@ -261,7 +260,8 @@ class Tests_get_installed_distributions:
         mock_dist_is_editable.side_effect = self.dist_is_editable
         mock_dist_is_local.side_effect = self.dist_is_local
         mock_dist_in_usersite.side_effect = self.dist_in_usersite
-        dists = get_installed_distributions(skip=freeze_excludes)
+        dists = get_installed_distributions(
+            skip=('setuptools', 'pip', 'distribute'))
         assert len(dists) == 0