解决PyCharm问题：module ‘pip’ has no attribute ‘main’

更新pip之后，PyCharm安装package出现如下报错：

module 'pip' has no attribute 'main'

找到安装目录下helpers/packaging_tool.py文件，修改如下代码：

def do_install(pkgs):
    try:
        # import pip
        try:
            from pip._internal import main
        except Exception:
            from pip import main
    except ImportError:
        error_no_pip()
    # return pip.main(['install'] + pkgs)
    return main(['install'] + pkgs)

def do_uninstall(pkgs):
    try:
        # import pip
        try:
            from pip._internal import main
        except Exception:
            from pip import main
    except ImportError:
        error_no_pip()
    # return pip.main(['uninstall', '-y'] + pkgs)
    return main(['uninstall', '-y'] + pkgs)