执行django-admin startproject my_site命令报错，请求技术协助

在CMD执行django-admin startproject my_site时触发报错，先后提示找不到zoneinfo和backports模块，已经尝试重装相关组件但问题仍未解决，影响Web开发学习进度。

报错详情 #

Traceback (most recent call last):
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\utils\timezone.py", line 10, in <module>
    import zoneinfo
ModuleNotFoundError: No module named 'zoneinfo'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\runpy.py", line 193, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "C:\Users\CHAYAN\AppData\Local\Programs\Python\Python39-32\Scripts\django-admin.exe\__main__.py", line 9, in <module>
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\core\management\__init__.py", line 446, in execute_from_command_line
    utility.execute()
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\core\management\__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\core\management\__init__.py", line 279, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\core\management\__init__.py", line 48, in load_command_class
    module = import_module("%s.management.commands.%s" % (app_name, name))
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1021, in _gcd_import
  File "<frozen importlib._bootstrap>", line 998, in _find_and_load
  File "<frozen importlib._bootstrap>", line 977, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 789, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\core\management\commands\startproject.py", line 2, in <module>
    from django.core.management.templates import TemplateCommand
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\core\management\templates.py", line 16, in <module>
    from django.template import Context, Engine
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\template\__init__.py", line 44, in <module>
    from .engine import Engine
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\template\engine.py", line7, in <module>
    from .base import Template
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\template\base.py", line 59, in <module>
    from django.utils.formats import localize
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\utils\formats.py", line 9, in <module>
    from django.utils import dateformat, numberformat
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\utils\dateformat.py", line 26, in <module>
    from django.utils.timezone import (
  File "c:\users\chayan\appdata\local\programs\python\python39-32\lib\site-packages\django\utils\timezone.py", line 12, in <module>
    from backports import zoneinfo
ModuleNotFoundError: No module named 'backports'

解决方案 #

• 问题根源：你使用的是Python 3.9，zoneinfo是Python 3.10及以上版本才内置的标准库。Django在低版本Python环境下会尝试导入第三方包backports.zoneinfo作为替代，但这个包没有安装，所以触发报错。
• 解决步骤：
  1. 打开CMD，执行以下命令安装backports.zoneinfo：

     pip install backports.zoneinfo
     

  2. 安装完成后如果仍报错，检查pip对应的Python版本是否和你当前使用的一致：执行pip --version，查看输出路径是否和报错信息里的Python路径（c:\users\chayan\appdata\local\programs\python\python39-32）匹配，若不匹配，改用python -m pip install backports.zoneinfo来确保安装到正确的环境。
  3. 若上述方法都无效，建议升级Python到3.10及以上版本，这样可以直接使用标准库的zoneinfo，无需额外安装第三方包。

内容的提问来源于stack exchange，提问作者Chayan Shukla