• 罗宾逊的 * 答案是正确的，但也可能是你忘记安装MySQL开发头和库了，比如：

$ sudo apt-get install default-libmysqlclient-dev

详细信息：https://pypi.org/project/mysqlclient/

相关信息如下：

Collecting mysqlclient
  Using cached mysqlclient-2.1.0.tar.gz (87 kB)
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error
  
  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [16 lines of output]
      /bin/sh: mysql_config: command not found
      /bin/sh: mariadb_config: command not found
      /bin/sh: mysql_config: command not found
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "/private/var/folders/zv/60vkqgms41v8zg76_n8rntg00000gn/T/pip-install-_nlyaw6p/mysqlclient_a781e05976524422b764a6902ff6fe88/setup.py", line 15, in <module>
          metadata, options = get_config()
        File "/private/var/folders/zv/60vkqgms41v8zg76_n8rntg00000gn/T/pip-install-_nlyaw6p/mysqlclient_a781e05976524422b764a6902ff6fe88/setup_posix.py", line 70, in get_config
          libs = mysql_config("libs")
        File "/private/var/folders/zv/60vkqgms41v8zg76_n8rntg00000gn/T/pip-install-_nlyaw6p/mysqlclient_a781e05976524422b764a6902ff6fe88/setup_posix.py", line 31, in mysql_config
          raise OSError("{} not found".format(_mysql_config_path))
      OSError: mysql_config not found
      mysql_config --version
      mariadb_config --version
      mysql_config --libs
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

这就是线索mysql_config：未找到命令
我通过定位命令在我的系统上的位置，并将其添加到$PATH来解决问题，在我的情况下如下所示：

export PATH=/usr/local/mysql-5.7.16-osx10.11-x86_64/bin:$PATH

显然，这条消息的意思是，在$PATH上找不到配置mysql的命令。现在我们知道了。

简短回答

sudo apt-get install python3.10-dev default-libmysqlclient-dev build-essential

python3.10-dev中的python版本应该是你使用的python版本。在我的例子中是3.10：

$ python3 --version
Python 3.10.6

详情

首先，我运行@levinson的命令：

sudo apt-get install default-libmysqlclient-dev

然后在pip install -r requirements.txt中，我得到了其他错误（相互继承）：

Building wheel for mysqlclient (setup.py) ... error
error: subprocess-exited-with-error
<...>
note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for mysqlclient
<...>
Running setup.py install for mysqlclient ... error
error: subprocess-exited-with-error
<...>
note: This error originates from a subprocess, and is likely not a problem with pip.
error: legacy-install-failure

在那之后，我发现了这篇文章，它建议执行这个命令：

# For Debian/ Ubuntu
sudo apt-get install python3-dev default-libmysqlclient-dev build-essential

但它给我错误，而安装python3-dev.之后，我发现有一个python3.x-dev包，并尝试3.10版本.它的工作！之后，我只是运行pip install -r requirements.txt和安装成功.

假设requirements.txt包含一个'import mysql'语句，MySQL documentation帮助可以通过两种方式解决这个问题：
1.由于mysql是一个“虚拟包”，请安装“MySQL-python（Python 2）或mysqlclient（Python 3）”
1.解析OS specific install dependencies
一旦依赖项被安装，你就可以通过安装mysql包来避免代码重写。

不确定这是否仍然有帮助。在我的情况下，我意识到这一点
sudo apt-get install default-libmysqlclient-dev
我安装了mysql客户端，但没有安装mysql服务器。我安装了mysql服务器：
sudo apt install mysql-server
这样就解决了问题