Defaulting to user installation because normal site-packages is not writeable
Collecting mysqlclient
  Using cached mysqlclient-2.2.0.tar.gz (89 kB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  error: subprocess-exited-with-error
  × Getting requirements to build wheel did not run successfully.
  │ exit code: 1
  ╰─> [25 lines of output]
      Trying pkg-config --exists mysqlclient
      Command 'pkg-config --exists mysqlclient' returned non-zero exit status 1.
      Trying pkg-config --exists mariadb
      Command 'pkg-config --exists mariadb' returned non-zero exit status 1.
      Traceback (most recent call last):
        File "/usr/lib/python3/dist-packages/pip/_vendor/pep517/in_process/_in_process.py", line 363, in 
          main()
        File "/usr/lib/python3/dist-packages/pip/_vendor/pep517/in_process/_in_process.py", line 345, in main
          json_out['return_val'] = hook(**hook_input['kwargs'])
        File "/usr/lib/python3/dist-packages/pip/_vendor/pep517/in_process/_in_process.py", line 130, in get_requires_for_build_wheel
          return hook(config_settings)
        File "/usr/lib/python3/dist-packages/setuptools/build_meta.py", line 162, in get_requires_for_build_wheel
          return self._get_build_requires(
        File "/usr/lib/python3/dist-packages/setuptools/build_meta.py", line 143, in _get_build_requires
          self.run_setup()
        File "/usr/lib/python3/dist-packages/setuptools/build_meta.py", line 158, in run_setup
          exec(compile(code, __file__, 'exec'), locals())
        File "setup.py", line 154, in 
          ext_options = get_config_posix(get_options())
        File "setup.py", line 48, in get_config_posix
          pkg_name = find_package_name()
        File "setup.py", line 27, in find_package_name
          raise Exception(
      Exception: Can not find valid pkg-config name.
      Specify MYSQLCLIENT_CFLAGS and MYSQLCLIENT_LDFLAGS env vars manually
      [end of output]
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error
× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> See above for output.
note: This error originates from a subprocess, and is likely not a problem with pip.

这个错误是我在使用pip安装mysqlclient时报错，意思是无法通过pkg-config找到MySQL客户端库，可能因为因为我没有设置mysql的环境变量MYSQLCLIENT_CFLAGS和 MYSQLCLIENT_LDFLAGS。所以需要手动指定MySQL的头文件和库路径:

前提因为我的已经安装了mysql数据库，我的mysql路径为usr/local/mysql

1. 1. 进入root模式，安装MySQL开发包

yum install mysql-devel

1. 2. 设置环境变量

• 使用whereis pkgconfig命令找到该文件夹

  

  • 将mysql/bin/pkgconfig文件夹中的文件复制到/usr/lib64/pkgconfig/中

    cp /usr/local/mysql/bin/pkgconfig/mysqlclient.pc /usr/lib64/pkgconfig/

    • 编辑/etc/profile文件

      vim /etc/profile

      在文件末补充添加以下行：

      export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/lib64/pkgconfig

      • 保存并关闭文件。
      • 重新加载/etc/profile文件，使更改生效：

        source /etc/profile

        现在可以通过运行以下命令来验证是否添加成功：

        echo $PKG_CONFIG_PATH

        我是这样弄得，或许可以直接将msql/bin中的pkgconfig文件夹路径设置为环境变量

        1. 3. 重新安装mysqlclient

        pip install mysqlclient