安装AioHttp时遇multidict模块缺失错误，求解决方法

你的错误根源在于安装aiohttp源码包时，前置依赖的multidict模块未被提前安装，再加上Python3.6搭配旧版pip的依赖解析逻辑存在缺陷，导致无法自动处理这类前置依赖需求。以下是几种可行的修复方案：

方法一：手动预安装依赖后再安装aiohttp #

1. 先升级pip到兼容Python3.6的最新版本，解决依赖解析bug：

pip3 install --upgrade pip

2. 安装与aiohttp 3.8.3完全兼容的multidict版本：

pip3 install multidict==5.2.0

3. 重新执行aiohttp安装命令：

pip3 install aiohttp==3.8.3

方法二：用构建隔离参数自动处理依赖 #

直接在安装aiohttp时添加--no-build-isolation参数，让pip在安装流程中自动处理所有依赖项：

pip3 install aiohttp --no-build-isolation

方法三：使用预编译wheel包避免源码编译 #

如果源码编译仍报错，先安装wheel工具，让pip优先下载预编译的二进制包，跳过源码编译环节：

pip3 install wheel
pip3 install aiohttp

你的报错日志： #

root@user:/home/user/server/user# pip3 install aiohttp
Collecting aiohttp
  Using cached https://files.pythonhosted.org/packages/ff/4f/62d9859b7d4e6dc32feda67815c5f5ab4421e6909e48cbc970b6a40d60b7/aiohttp-3.8.3.tar.gz
    Complete output from command python setup.py egg_info:
    *********************
    * Accelerated build *
    *********************
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-0b29nbfp/aiohttp/setup.py", line 54, in <module>
        setup(**setup_kwargs)
      File "/usr/lib/python3/dist-packages/setuptools/__init__.py", line 129, in setup
        return distutils.core.setup(**attrs)
      File "/usr/lib/python3.6/distutils/core.py", line 121, in setup
        dist.parse_config_files()
      File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 494, in parse_config_files
        ignore_option_errors=ignore_option_errors)
      File "/usr/lib/python3/dist-packages/setuptools/config.py", line 106, in parse_configuration
        meta.parse()
      File "/usr/lib/python3/dist-packages/setuptools/config.py", line 382, in parse
        section_parser_method(section_options)
      File "/usr/lib/python3/dist-packages/setuptools/config.py", line 355, in parse_section
        self[name] = value
      File "/usr/lib/python3/dist-packages/setuptools/config.py", line 173, in __setitem__
        value = parser(value)
      File "/usr/lib/python3/dist-packages/setuptools/config.py", line 430, in _parse_version
        version = self._parse_attr(value)
      File "/usr/lib/python3/dist-packages/setuptools/config.py", line 305, in _parse_attr
        module = import_module(module_name)
      File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
      File "<frozen importlib._bootstrap>", line 994, in _gcd_import
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
      File "<frozen importlib._bootstrap_external>", line 678, in exec_module
      File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
      File "/tmp/pip-build-0b29nbfp/aiohttp/aiohttp/__init__.py", line 5, in <module>
        from . import hdrs as hdrs
      File "/tmp/pip-build-0b29nbfp/aiohttp/aiohttp/hdrs.py", line 8, in <module>
        from multidict import istr
    ModuleNotFoundError: No module named 'multidict'

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-0b29nbfp/aiohttp/

内容的提问来源于stack exchange，提问作者Niks