packages.py 文件源码

def pip_execute(*args, **kwargs):
    """Overriden pip_execute() to stop sys.path being changed.

    The act of importing main from the pip module seems to cause add wheels
    from the /usr/share/python-wheels which are installed by various tools.
    This function ensures that sys.path remains the same after the call is
    executed.
    """
    try:
        _path = sys.path
        try:
            from pip import main as _pip_execute
        except ImportError:
            apt_update()
            apt_install('python-pip')
            from pip import main as _pip_execute
        _pip_execute(*args, **kwargs)
    finally:
        sys.path = _path