Windows 8.1 x64系统中Python安装后无法安装pip，出现pyexpat DLL加载失败错误

我在Windows 8.1 x64的电脑上安装Python，试了好几个版本都遇到同一个问题——pip总是装不上。一开始用的Python 3.13，后来换成3.11、3.10（全是x64版本），最后试了3.9，结果还是一样。

我运行python -m pip时，得到的错误提示是：

%USERPROFILE%\AppData\Local\Programs\Python\Python39\python.exe: No module named pip

之后我尝试用python get-pip.py来安装pip，结果又抛出了如下的回溯错误：

Traceback (most recent call last):
  File "%USERPROFILE%\Desktop\get-pip.py", line 28840, in <module>
    main()
  File "%USERPROFILE%\Desktop\get-pip.py", line 137, in main
    bootstrap(tmpdir=tmpdir)
  File "%USERPROFILE%\Desktop\get-pip.py", line 113, in bootstrap
    monkeypatch_for_cert(tmpdir)
  File "%USERPROFILE%\Desktop\get-pip.py", line 94, in monkeypatch_for_cert
    from pip._internal.commands.install import InstallCommand
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_internal\commands\install.py", line 19, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_internal\self_outdated_check.py", line 19, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_internal\index\package_finder.py", line 31, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_internal\req\__init__.py", line 9, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_internal\req\req_install.py", line 40, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_internal\operations\install\wheel.py", line 40, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_vendor\distlib\scripts.py", line 16, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\AppData\Local\Temp\tmpt_m_1ou9\pip.zip\pip\_vendor\distlib\compat.py", line 81, in <module>
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\xmlrpc\client.py", line 138, in <module>
    from xml.parsers import expat
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\xml\parsers\expat.py", line 4, in <module>
    from pyexpat import *
ImportError: DLL load failed while importing pyexpat: No se puede encontrar el módulo especificado.

我还试了python pip.pyz install pip（其实我知道直接用pip.pyz install pip也行，但还是试了这个命令），结果得到的错误和上面几乎一样：

Traceback (most recent call last):
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "%USERPROFILE%\Desktop\pip.pyz\__main__.py", line 26, in <module>
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 228, in run_module
    return _run_code(code, {}, init_globals, run_name, mod_spec)
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "%USERPROFILE%\Desktop\pip.pyz\pip\__main__.py", line 24, in <module>
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\cli\main.py", line 78, in main
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\commands\__init__.py", line 114, in create_command
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 664, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 627, in _load_backward_compatible
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\commands\install.py", line 19, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\self_outdated_check.py", line 19, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\index\package_finder.py", line 31, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\req\__init__.py", line 9, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\req\req_install.py", line 40, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_internal\operations\install\wheel.py", line 40, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_vendor\distlib\scripts.py", line 16, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "%USERPROFILE%\Desktop\pip.pyz\pip\_vendor\distlib\compat.py", line 81, in <module>
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\xmlrpc\client.py", line 138, in <module>
    from xml.parsers import expat
  File "%USERPROFILE%\AppData\Local\Programs\Python\Python39\lib\xml\parsers\expat.py", line 4, in <module>
    from pyexpat import *
ImportError: DLL load failed while importing pyexpat: No se puede encontrar el módulo especificado.

最后我尝试用python -m ensurepip来修复pip，还是得到了类似的错误回溯：

Traceback (most recent call last):
  File "<string>", line 6, in <module>
  File "C:\Users\USER\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 225, in run_module
    return _run_module_code(code, init_globals, run_name, mod_spec)
  File "C:\Users\USER\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 97, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "C:\Users\USER\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\__main__.py", line 31, in <module>
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\cli\main.py", line 68, in main
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\commands\__init__.py", line 109, in create_command
  File "C:\Users\USER\AppData\Local\Programs\Python\Python39\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 664, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 627, in _load_backward_compatible
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\commands\install.py", line 14, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\cli\req_command.py", line 21, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\index\package_finder.py", line 32, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\req\__init__.py", line 8, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\req\req_install.py", line 39, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_internal\operations\install\wheel.py", line 38, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_vendor\distlib\scripts.py", line 14, in <module>
  File "<frozen zipimport>", line 259, in load_module
  File "C:\Users\USER\AppData\Local\Temp\tmpfwcx6id7\pip-22.0.4-py3-none-any.whl\pip\_vendor\distlib\compat.py", line 81, in <module>
  File "C:\Users\USER\AppData\Local\Programs\Python\Python39\lib\xmlrpc\client.py", line 138, in <module>
    from xml.parsers import expat
  File "C:\Users\USER\AppData\Local\Programs\Python\Python39\lib\xml\parsers\expat.py", line 4, in <module>
    from pyexpat import *
ImportError: DLL load failed while importing pyexpat: No se puede encontrar el módulo especificado.

备注：内容来源于stack exchange，提问作者Jerardo