__init__.py 文件源码

def _uninstall_helper(verbosity=0):
    """Helper to support a clean default uninstall process on Windows

    Note that calling this function may alter os.environ.
    """
    # Nothing to do if pip was never installed, or has been removed
    try:
        import pip
    except ImportError:
        return

    # If the pip version doesn't match the bundled one, leave it alone
    if pip.__version__ != _PIP_VERSION:
        msg = ("ensurepip will only uninstall a matching version "
               "({!r} installed, {!r} bundled)")
        print(msg.format(pip.__version__, _PIP_VERSION), file=sys.stderr)
        return

    _disable_pip_configuration_settings()

    # Construct the arguments to be passed to the pip command
    args = ["uninstall", "-y", "--disable-pip-version-check"]
    if verbosity:
        args += ["-" + "v" * verbosity]

    _run_pip(args + [p[0] for p in reversed(_PROJECTS)])