my-first-blog/myvenv/Lib/site-packages/pip/_internal/commands/uninstall.py

# The following comment should be removed at some point in the future.
# mypy: disallow-untyped-defs=False

from __future__ import absolute_import

from pip._vendor.packaging.utils import canonicalize_name

from pip._internal.cli.base_command import Command
from pip._internal.cli.req_command import SessionCommandMixin
from pip._internal.exceptions import InstallationError
from pip._internal.req import parse_requirements
from pip._internal.req.constructors import install_req_from_line
from pip._internal.utils.misc import protect_pip_from_modification_on_windows


class UninstallCommand(Command, SessionCommandMixin):
    """
    Uninstall packages.

    pip is able to uninstall most installed packages. Known exceptions are:

    - Pure distutils packages installed with ``python setup.py install``, which
      leave behind no metadata to determine what files were installed.
    - Script wrappers installed by ``python setup.py develop``.
    """

    usage = """
      %prog [options] <package> ...
      %prog [options] -r <requirements file> ..."""

    def __init__(self, *args, **kw):
        super(UninstallCommand, self).__init__(*args, **kw)
        self.cmd_opts.add_option(
            '-r', '--requirement',
            dest='requirements',
            action='append',
            default=[],
            metavar='file',
            help='Uninstall all the packages listed in the given requirements '
                 'file.  This option can be used multiple times.',
        )
        self.cmd_opts.add_option(
            '-y', '--yes',
            dest='yes',
            action='store_true',
            help="Don't ask for confirmation of uninstall deletions.")

        self.parser.insert_option_group(0, self.cmd_opts)

    def run(self, options, args):
        session = self.get_default_session(options)

        reqs_to_uninstall = {}
        for name in args:
            req = install_req_from_line(
                name, isolated=options.isolated_mode,
            )
            if req.name:
                reqs_to_uninstall[canonicalize_name(req.name)] = req
        for filename in options.requirements:
            for req in parse_requirements(
                    filename,
                    options=options,
                    session=session):
                if req.name:
                    reqs_to_uninstall[canonicalize_name(req.name)] = req
        if not reqs_to_uninstall:
            raise InstallationError(
                'You must give at least one requirement to %(name)s (see '
                '"pip help %(name)s")' % dict(name=self.name)
            )

        protect_pip_from_modification_on_windows(
            modifying_pip="pip" in reqs_to_uninstall
        )

        for req in reqs_to_uninstall.values():
            uninstall_pathset = req.uninstall(
                auto_confirm=options.yes, verbose=self.verbosity > 0,
            )
            if uninstall_pathset:
                uninstall_pathset.commit()