降级Pip至18.0版本后无法运行，出现ImportError报错求助

问题描述 #

执行sudo python -m pip install pip==18.0 --upgrade将pip降级至18.0版本后，运行pip/pip3或尝试pip3 install --upgrade pip升级时，触发以下错误：

Traceback (most recent call last):
File "/usr/local/bin/pip3", line 5, in <module>
from pip._internal import main
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_internal/__init__.py", line 42, in <module>
from pip._internal import cmdoptions
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_internal/cmdoptions.py", line 16, in <module>
from pip._internal.index import (
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_internal/index.py", line 14, in <module>
from pip._vendor import html5lib, requests, six
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_vendor/html5lib/__init__.py", line 25, in <module>
from .html5parser import HTMLParser, parse, parseFragment
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_vendor/html5lib/html5parser.py", line 8, in <module>
from . import _tokenizer
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_vendor/html5lib/_tokenizer.py", line 16, in <module>
from ._trie import Trie
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_vendor/html5lib/_trie/__init__.py", line 3, in <module>
from .py import Trie as PyTrie
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_vendor/html5lib/_trie/py.py", line 6, in <module>
from ._base import Trie as ABCTrie
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pip/_vendor/html5lib/_trie/_base.py", line 3, in <module>
from collections import Mapping
ImportError: cannot import name 'Mapping' from 'collections' (/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/collections/__init__.py)

问题根源 #

Python 3.10中，collections.Mapping已被迁移至collections.abc模块，而pip 18.0是2018年发布的老旧版本，其内置的html5lib依赖仍在使用已被移除的collections.Mapping，导致兼容性错误。

解决方法 #

方法1：使用Python内置的ensurepip修复 #

执行以下命令，通过Python自带的ensurepip模块重新安装适配当前Python版本的pip：

sudo python3 -m ensurepip --upgrade

方法2：手动安装pip #

如果ensurepip无法解决问题，可通过官方脚本重新安装：

1. 获取get-pip.py脚本（从Python官方pip项目获取）
2. 执行安装命令：

sudo python3 get-pip.py

验证修复 #

执行以下命令确认pip版本已更新至兼容Python 3.10的版本（建议21.0及以上）：

pip3 --version

内容的提问来源于stack exchange，提问作者koifish5242