[WIP] Implement working scheme

src/pip/_internal/commands/download.py

@@ -203,7 +203,7 @@ def run(self, options, args):
  finder=finder,
  session=session,
  wheel_cache=None,
- use_user_site=False,
+ working_scheme="global",
  upgrade_strategy="to-satisfy-only",
  force_reinstall=False,
  ignore_dependencies=options.ignore_dependencies,

src/pip/_internal/commands/install.py

@@ -5,20 +5,25 @@
 import operator
 import os
 import shutil
+import site
 
 from pip._internal import cmdoptions
 from pip._internal.basecommand import RequirementCommand
 from pip._internal.cache import WheelCache
 from pip._internal.exceptions import (
  CommandError, InstallationError, PreviousBuildDirError
 )
-from pip._internal.locations import distutils_scheme, virtualenv_no_global
+from pip._internal.locations import (
+ distutils_scheme, running_under_virtualenv, virtualenv_no_global
+)
 from pip._internal.operations.prepare import RequirementPreparer
 from pip._internal.req import RequirementSet
 from pip._internal.resolve import Resolver
 from pip._internal.status_codes import ERROR
 from pip._internal.utils.filesystem import check_path_owner
-from pip._internal.utils.misc import ensure_dir, get_installed_version
+from pip._internal.utils.misc import (
+ ensure_dir, get_installed_version, guess_correct_working_scheme
+)
 from pip._internal.utils.temp_dir import TempDirectory
 from pip._internal.wheel import WheelBuilder
 
@@ -75,14 +80,37 @@ def __init__(self, *args, **kw):
  '<dir>. Use --upgrade to replace existing packages in <dir> '
  'with new versions.'
  )
+
+ cmd_opts.add_option(
+ '--scheme',
+ dest='working_scheme',
+ default=None,
+ help=(
+ "Determines where to install the package. Valid values are "
+ "global, user and venv."
+ )
+ )
+
  cmd_opts.add_option(
  '--user',
  dest='use_user_site',
  action='store_true',
- help="Install to the Python user install directory for your "
- "platform. Typically ~/.local/, or %APPDATA%\\Python on "
- "Windows. (See the Python documentation for site.USER_BASE "
- "for full details.)")
+ help=(
+ "Shorthand for --scheme user; if --scheme is passed, "
+ "this option is ignored."
+ ),
+ )
+
+ cmd_opts.add_option(
+ '--global',
+ dest='use_global_site',
+ action='store_true',
+ help=(
+ "Shorthand for --scheme global; if --scheme is passed, "
+ "this option is ignored."
+ ),
+ )
+
  cmd_opts.add_option(
  '--root',
  dest='root_path',
@@ -192,17 +220,67 @@ def run(self, options, args):
 
  options.src_dir = os.path.abspath(options.src_dir)
  install_options = options.install_options or []
- if options.use_user_site:
+
+ # When not passed a scheme, try to figure out what scheme to be used.
+ # Also handles --user and --global.
+ if options.working_scheme is None:
+ if options.use_user_site and options.use_global_site:
+ raise CommandError(
+ "Unable to determine which scheme to use for "
+ "installation (got both --global and --user). "
+ "Please specify scheme explicitly using --scheme."
+ )
+ elif options.use_user_site or options.use_global_site:
+ if options.use_user_site:
+ options.working_scheme = "user"
+ else:
+ assert options.use_global_site
+ options.working_scheme = "global"
+ # If we're in an virtualenv, we want to use the venv scheme.
+ elif running_under_virtualenv():
+ options.working_scheme = "venv"
+ # user scheme doesn't make sense if user site-packages is disabled
+ # or if a prefix is to be used.
+ elif not site.ENABLE_USER_SITE or options.prefix_path:
+ options.working_scheme = "global"
+ else:
+ # NOTE: We do backwards compatibility checks here. Eventually,
+ # this line should just be:
+ # options.working_scheme = "user"
+ options.working_scheme = guess_correct_working_scheme()
+
+ # Ensure no one can ever depend on these variables.
+ del options.use_global_site
+ del options.use_user_site
+
+ # Ensure the given scheme is a valid one.
+ if options.working_scheme not in ["user", "global", "venv"]:
+ raise CommandError(
+ "Got unknown scheme {!r}. "
+ "Should be one of 'global', 'user' or 'venv'."
+ .format(options.working_scheme)
+ )
+
+ # Sanity checks for working schemes
+ if options.working_scheme == "venv":
+ if not running_under_virtualenv():
+ raise CommandError(
+ "Can not use 'venv' scheme when a virtualenv is not "
+ "active."
+ )
+ options.require_venv = True
+ elif options.working_scheme == "user":
  if options.prefix_path:
  raise CommandError(
- "Can not combine '--user' and '--prefix' as they imply "
- "different installation locations"
+ "Can not combine '--scheme user' and '--prefix' as they "
+ "imply different installation locations."
  )
  if virtualenv_no_global():
  raise InstallationError(
- "Can not perform a '--user' install. User site-packages "
- "are not visible in this virtualenv."
+ "Can not perform a user scheme install. User "
+ "site-packages are not visible in this virtualenv."
  )
+
  install_options.append('--user')
  install_options.append('--prefix=')
 
@@ -246,7 +324,7 @@ def run(self, options, args):
  target_dir=target_temp_dir.path,
  pycompile=options.compile,
  require_hashes=options.require_hashes,
- use_user_site=options.use_user_site,
+ working_scheme=options.working_scheme,
  )
 
  self.populate_requirement_set(
@@ -266,7 +344,7 @@ def run(self, options, args):
  finder=finder,
  session=session,
  wheel_cache=wheel_cache,
- use_user_site=options.use_user_site,
+ working_scheme=options.working_scheme,
  upgrade_strategy=upgrade_strategy,
  force_reinstall=options.force_reinstall,
  ignore_dependencies=options.ignore_dependencies,
@@ -301,7 +379,7 @@ def run(self, options, args):
  )
 
  possible_lib_locations = get_lib_location_guesses(
- user=options.use_user_site,
+ user=options.working_scheme == "user",
  home=target_temp_dir.path,
  root=options.root_path,
  prefix=options.prefix_path,
@@ -326,11 +404,11 @@ def run(self, options, args):
  except EnvironmentError as e:
  message_parts = []
 
- user_option_part = "Consider using the `--user` option"
+ user_option_part = "Consider using `--scheme user` option"
  permissions_part = "Check the permissions"
 
  if e.errno == errno.EPERM:
- if not options.use_user_site:
+ if options.working_scheme != "user":
  message_parts.extend([
  user_option_part, " or ",
  permissions_part.lower(),

src/pip/_internal/commands/wheel.py

@@ -164,7 +164,7 @@ def run(self, options, args):
  finder=finder,
  session=session,
  wheel_cache=wheel_cache,
- use_user_site=False,
+ working_scheme="global",
  upgrade_strategy="to-satisfy-only",
  force_reinstall=False,
  ignore_dependencies=options.ignore_dependencies,

src/pip/_internal/req/req_install.py

@@ -115,7 +115,7 @@ def __init__(self, req, comes_from, source_dir=None, editable=False,
  self.install_succeeded = None
  # UninstallPathSet of uninstalled distribution (for possible rollback)
  self.uninstalled_pathset = None
- self.use_user_site = False
+ self.working_scheme = "global"
  self.target_dir = None
  self.options = options if options else {}
  self.pycompile = pycompile
@@ -840,7 +840,7 @@ def get_install_args(self, global_options, record_filename, root, prefix):
  else:
  install_args += ["--no-compile"]
 
- if running_under_virtualenv():
+ if self.working_scheme == "venv":
  py_ver_str = 'python' + sysconfig.get_python_version()
  install_args += ['--install-headers',
  os.path.join(sys.prefix, 'include', 'site',
@@ -913,7 +913,7 @@ def check_if_exists(self):
  existing_dist = pkg_resources.get_distribution(
  self.req.name
  )
- if self.use_user_site:
+ if self.working_scheme == "user":
  if dist_in_usersite(existing_dist):
  self.conflicts_with = existing_dist
  elif (running_under_virtualenv() and
@@ -935,7 +935,7 @@ def move_wheel_files(self, wheeldir, root=None, prefix=None,
  warn_script_location=True):
  move_wheel_files(
  self.name, self.req, wheeldir,
- user=self.use_user_site,
+ user=self.working_scheme == "user",
  home=self.target_dir,
  root=root,
  prefix=prefix,

src/pip/_internal/req/req_set.py

@@ -13,8 +13,8 @@
 class RequirementSet(object):
 
  def __init__(self,
- require_hashes=False, target_dir=None, use_user_site=False,
- pycompile=True):
+ require_hashes=False, target_dir=None,
+ working_scheme="global", pycompile=True):
  """Create a RequirementSet.
 
  :param wheel_cache: The pip wheel cache, for passing to
@@ -29,7 +29,7 @@ def __init__(self,
  self.unnamed_requirements = []
  self.successfully_downloaded = []
  self.reqs_to_cleanup = []
- self.use_user_site = use_user_site
+ self.working_scheme = working_scheme
  self.target_dir = target_dir # set from --target option
  self.pycompile = pycompile
  # Maps from install_req -> dependencies_of_install_req
@@ -81,7 +81,7 @@ def add_requirement(self, install_req, parent_req_name=None,
  wheel.filename
  )
 
- install_req.use_user_site = self.use_user_site
+ install_req.working_scheme = self.working_scheme
  install_req.target_dir = self.target_dir
  install_req.pycompile = self.pycompile
  install_req.is_direct = (parent_req_name is None)

src/pip/_internal/resolve.py

@@ -32,7 +32,7 @@ class Resolver(object):
 
  _allowed_strategies = {"eager", "only-if-needed", "to-satisfy-only"}
 
- def __init__(self, preparer, session, finder, wheel_cache, use_user_site,
+ def __init__(self, preparer, session, finder, wheel_cache, working_scheme,
  ignore_dependencies, ignore_installed, ignore_requires_python,
  force_reinstall, isolated, upgrade_strategy):
  super(Resolver, self).__init__()
@@ -54,7 +54,7 @@ def __init__(self, preparer, session, finder, wheel_cache, use_user_site,
  self.ignore_dependencies = ignore_dependencies
  self.ignore_installed = ignore_installed
  self.ignore_requires_python = ignore_requires_python
- self.use_user_site = use_user_site
+ self.working_scheme = working_scheme
 
  def resolve(self, requirement_set):
  """Resolve what operations need to be done
@@ -120,7 +120,7 @@ def _set_req_to_reinstall(self, req):
  """
  # Don't uninstall the conflict if doing a user install and the
  # conflict is not a user install.
- if not self.use_user_site or dist_in_usersite(req.satisfied_by):
+ if self.working_scheme != "user" or dist_in_usersite(req.satisfied_by):
  req.conflicts_with = req.satisfied_by
  req.satisfied_by = None
 

src/pip/_internal/utils/misc.py

@@ -15,6 +15,7 @@
 import subprocess
 import sys
 import tarfile
+import tempfile
 import zipfile
 from collections import deque
 
@@ -28,8 +29,8 @@
 from pip._internal.compat import console_to_str, expanduser, stdlib_pkgs
 from pip._internal.exceptions import InstallationError
 from pip._internal.locations import (
- running_under_virtualenv, site_packages, user_site, virtualenv_no_global,
- write_delete_marker_file
+ distutils_scheme, running_under_virtualenv, site_packages, user_site,
+ virtualenv_no_global, write_delete_marker_file
 )
 
 if PY2:
@@ -877,3 +878,38 @@ def enum(*sequential, **named):
  reverse = dict((value, key) for key, value in enums.items())
  enums['reverse_mapping'] = reverse
  return type('Enum', (), enums)
+
+
+def guess_correct_working_scheme():
+ # XXX: This is purely for addressing backwards compatibility concerns.
+
+ def _can_create_file_in(folder_path):
+ """Returns whether a file can be created in the given folder
+ """
+ # If the given folder does not exist, try to create it. If there's
+ # going to be a successful installation, the folder probably needs to
+ # be created anyway.
+ try:
+ ensure_dir(folder_path)
+ except EnvironmentError:
+ return False
+
+ # Try to create a temporary file in the folder and delete it.
+ try:
+ with tempfile.TemporaryFile(dir=folder_path):
+ pass
+ except EnvironmentError:
+ return False
+
+ return True
+
+ # This is the "smart" portion. Check if there's any potential global folder
+ # for which pip doesn't have the required permissions. If there's any such
+ # location, pip should perform a user installation instead.
+ for folder in distutils_scheme("").values():
+ if not _can_create_file_in(folder):
+ return "user"
+
+ # Assume the user wants to do a global installation. This is the most
+ # backwards compatible policy; preserving behaviour for `sudo pip install`
+ return "global"

tests/functional/test_install.py

@@ -708,7 +708,7 @@ def test_install_package_conflict_prefix_and_user(script, data):
  expect_error=True, quiet=True,
  )
  assert (
- "Can not combine '--user' and '--prefix'" in result.stderr
+ "Can not combine '--scheme user' and '--prefix'" in result.stderr
  )
 
 

tests/functional/test_install_user.py

@@ -66,7 +66,7 @@ def test_install_subversion_usersite_editable_with_distribute(
  tmpdir.join("cache"),
  )
  )
- result.assert_installed('INITools', use_user_site=True)
+ result.assert_installed('INITools', in_user_site=True)
 
  def test_install_curdir_usersite(self, script, virtualenv, data):
  """
@@ -98,8 +98,8 @@ def test_install_user_venv_nositepkgs_fails(self, script, data):
  expect_error=True,
  )
  assert (
- "Can not perform a '--user' install. User site-packages are not "
- "visible in this virtualenv." in result.stderr
+ "Can not perform a user scheme install. User site-packages are "
+ "not visible in this virtualenv." in result.stderr
  )
 
  @pytest.mark.network