Python版本-3.7我嘗試使用 pip 安裝 pyInstaller。我在 cmd 中收到以下輸出和錯誤消息。錯誤信息Collecting pyinstaller  Using cached pyinstaller-4.0.tar.gz (3.5 MB)  Installing build dependencies ... error  ERROR: Command errored out with exit status 1:   command: 'C:\Users\dell\AppData\Local\Programs\Python\Python37\python.exe' 'C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\dell\AppData\Local\Temp\pip-build-env-d_vuoc7m\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- 'setuptools>=40.8.0' wheel       cwd: None  Complete output (14 lines):  Traceback (most recent call last):    File "C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 193, in _run_module_as_main      "__main__", mod_spec)    File "C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code      exec(code, run_globals)    File "C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\site-packages\pip\__main__.py", line 23, in <module>      from pip._internal.cli.main import main as _main  # isort:skip # noqa    File "C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\site-packages\pip\_internal\cli\main.py", line 5, in <module>      import locale    File "C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\locale.py", line 16, in <module>      import re    File "C:\Users\dell\AppData\Local\Programs\Python\Python37\lib\re.py", line 143, in <module>      class RegexFlag(enum.IntFlag):  AttributeError: module 'enum' has no attribute 'IntFlag'  ----------------------------------------