Added a --target parameter to uninstall to allow uninstalling from custom folders

pip/commands/uninstall.py

@@ -35,6 +35,12 @@ def __init__(self, *args, **kw):
             dest='yes',
             action='store_true',
             help="Don't ask for confirmation of uninstall deletions.")
+        self.cmd_opts.add_option(
+            '-t', '--target',
+            dest='target',
+            default=None,
+            help="Uninstall from a target directory.  This is similar to the "
+                 "flag of same name on the install command.")
 
         self.parser.insert_option_group(0, self.cmd_opts)
 
@@ -61,4 +67,5 @@ def run(self, options, args):
                 'You must give at least one requirement to %(name)s (see "pip '
                 'help %(name)s")' % dict(name=self.name)
             )
-        requirement_set.uninstall(auto_confirm=options.yes)
+        requirement_set.uninstall(auto_confirm=options.yes,
+                                  target=options.target)

pip/req/req_install.py

@@ -519,26 +519,30 @@ def update_editable(self, obtain=True):
                 'Unexpected version control type (in %s): %s'
                 % (self.url, vc_type))
 
-    def uninstall(self, auto_confirm=False):
+    def uninstall(self, auto_confirm=False, target=None):
         """
         Uninstall the distribution currently satisfying this requirement.
 
         Prompts before removing or modifying files unless
         ``auto_confirm`` is True.
 
+        The `target` parameter optionally defines a target folder
+        which is considered for deinstallation instead of the
+        system site packages.
+
         Refuses to delete or modify files outside of ``sys.prefix`` -
         thus uninstallation within a virtual environment can only
         modify that virtual environment, even if the virtualenv is
         linked to global site-packages.
 
         """
-        if not self.check_if_exists():
+        if not self.check_if_exists(target=target):
             raise UninstallationError(
                 "Cannot uninstall requirement %s, not installed" % (self.name,)
             )
         dist = self.satisfied_by or self.conflicts_with
 
-        paths_to_remove = UninstallPathSet(dist)
+        paths_to_remove = UninstallPathSet(dist, target=target)
 
         pip_egg_info_path = os.path.join(dist.location,
                                          dist.egg_name()) + '.egg-info'
@@ -875,13 +879,29 @@ def _filter_install(self, line):
                 break
         return (level, line)
 
-    def check_if_exists(self):
+    def check_if_exists(self, target=None):
         """Find an installed distribution that satisfies or conflicts
         with this requirement, and set self.satisfied_by or
         self.conflicts_with appropriately."""
 
         if self.req is None:
             return False
+
+        if target is not None:
+            working_set = pkg_resources.WorkingSet()
+            working_set.add_entry(target)
+        else:
+            working_set = pkg_resources.working_set
+
+        def _get_dist(req):
+            # This does pretty much exactly the same logic as the
+            # get_distribution function in pkg_resources through two
+            # layers of indirection but it works with an explicit working
+            # set instead.
+            if isinstance(req, six.string_types):
+                req = pkg_resources.Requirement.parse(req)
+            return working_set.find(req) or working_set.require(str(req))[0]
+
         try:
             # DISTRIBUTE TO SETUPTOOLS UPGRADE HACK (1 of 3 parts)
             # if we've already set distribute as a conflict to setuptools
@@ -893,13 +913,11 @@ def check_if_exists(self):
                     and self.conflicts_with.project_name == 'distribute'):
                 return True
             else:
-                self.satisfied_by = pkg_resources.get_distribution(self.req)
+                self.satisfied_by = _get_dist(self.req)
         except pkg_resources.DistributionNotFound:
             return False
         except pkg_resources.VersionConflict:
-            existing_dist = pkg_resources.get_distribution(
-                self.req.project_name
-            )
+            existing_dist = _get_dist(self.req.project_name)
             if self.use_user_site:
                 if dist_in_usersite(existing_dist):
                     self.conflicts_with = existing_dist

pip/req/req_set.py

@@ -146,9 +146,9 @@ def get_requirement(self, project_name):
                 return self.requirements[self.requirement_aliases[name]]
         raise KeyError("No project with the name %r" % project_name)
 
-    def uninstall(self, auto_confirm=False):
+    def uninstall(self, auto_confirm=False, target=None):
         for req in self.requirements.values():
-            req.uninstall(auto_confirm=auto_confirm)
+            req.uninstall(auto_confirm=auto_confirm, target=target)
             req.commit_uninstall()
 
     def locate_files(self):

pip/req/req_uninstall.py

@@ -13,9 +13,10 @@
 class UninstallPathSet(object):
     """A set of file paths to be removed in the uninstallation of a
     requirement."""
-    def __init__(self, dist):
+    def __init__(self, dist, target=None):
         self.paths = set()
         self._refuse = set()
+        self.target = target
         self.pth = {}
         self.dist = dist
         self.save_dir = None
@@ -27,10 +28,10 @@ def _permitted(self, path):
         remove/modify, False otherwise.
 
         """
-        return is_local(path)
+        return is_local(path, target=self.target)
 
     def _can_uninstall(self):
-        if not dist_is_local(self.dist):
+        if not dist_is_local(self.dist, self.target):
             logger.notify(
                 "Not uninstalling %s at %s, outside environment %s" %
                 (
@@ -115,7 +116,7 @@ def remove(self, auto_confirm=False):
                     new_path = self._stash(path)
                     logger.info('Removing file or directory %s' % path)
                     self._moved_paths.append(path)
-                    renames(path, new_path)
+                    renames(path, new_path, preserve=self.target)
                 for pth in self.pth.values():
                     pth.remove()
                 logger.notify(

pip/util.py

@@ -292,8 +292,11 @@ def splitext(path):
     return base, ext
 
 
-def renames(old, new):
-    """Like os.renames(), but handles renaming across devices."""
+def renames(old, new, preserve=None):
+    """Like os.renames(), but handles renaming across devices.  The
+    preserve flag can be used to define a directory that will not be
+    deleted.
+    """
     # Implementation borrowed from os.renames().
     head, tail = os.path.split(new)
     if head and tail and not os.path.exists(head):
@@ -302,14 +305,15 @@ def renames(old, new):
     shutil.move(old, new)
 
     head, tail = os.path.split(old)
-    if head and tail:
+    if head and tail and (preserve is None or
+                          normalize_path(head) != normalize_path(preserve)):
         try:
             os.removedirs(head)
         except OSError:
             pass
 
 
-def is_local(path):
+def is_local(path, target=None):
     """
     Return True if path is within sys.prefix, if we're running in a virtualenv.
 
@@ -318,18 +322,24 @@ def is_local(path):
     """
     if not running_under_virtualenv():
         return True
-    return normalize_path(path).startswith(normalize_path(sys.prefix))
+    norm_path = normalize_path(path)
+    for valid_root in sys.prefix, target:
+        if valid_root is None:
+            continue
+        if norm_path.startswith(normalize_path(valid_root)):
+            return True
+    return False
 
 
-def dist_is_local(dist):
+def dist_is_local(dist, target=None):
     """
     Return True if given Distribution object is installed locally
     (i.e. within current virtualenv).
 
     Always True if we're not in a virtualenv.
 
     """
-    return is_local(dist_location(dist))
+    return is_local(dist_location(dist), target=target)
 
 
 def dist_in_usersite(dist):

tests/functional/test_uninstall.py

@@ -8,6 +8,7 @@
 from mock import patch
 from tests.lib import assert_all_changes, pyversion
 from tests.lib.local_repos import local_repo, local_checkout
+from tests.lib.path import Path
 
 from pip.util import rmtree
 
@@ -355,3 +356,30 @@ def test_uninstall_wheel(script, data):
     assert dist_info_folder in result.files_created
     result2 = script.pip('uninstall', 'simple.dist', '-y')
     assert_all_changes(result, result2, [])
+
+
+def test_uninstall_package_with_target(script, data):
+    """
+    Test uninstalling a package from a target.
+    """
+    target_dir = script.scratch_path / 'target'
+    result = script.pip('install', '-t', target_dir, 'initools==0.1')
+    pkg_path = Path('scratch') / 'target' / 'initools'
+    assert pkg_path in result.files_created, (str(result))
+    result2 = script.pip('uninstall', 'initools', '-y', '-t', target_dir)
+    assert_all_changes(result, result2, [])
+
+
+def test_uninstall_wheel_with_target(script, data):
+    """
+    Test uninstalling a package from a target.
+    """
+    target_dir = script.scratch_path / 'target'
+    package = data.packages.join("simple.dist-0.1-py2.py3-none-any.whl")
+    result = script.pip('install', package, '--no-index', '-t', target_dir)
+    pkg_path = Path('scratch') / 'target' / 'simpledist'
+    assert pkg_path in result.files_created, (str(result))
+    dist_info_folder = Path('scratch') / 'target' / 'simple.dist-0.1.dist-info'
+    assert dist_info_folder in result.files_created
+    result2 = script.pip('uninstall', 'simple.dist', '-y', '-t', target_dir)
+    assert_all_changes(result, result2, [])