Pymysql 无法连接到 MySQL DB：挂在“self.socket.recv_into(b)”处？答案

【问题标题】：Pymysql can't connect do MySQL DB: hangs at "self.sock.recv_into(b)"?Pymysql 无法连接到 MySQL DB：挂在“self.socket.recv_into(b)”处？
【发布时间】：2020-06-04 14:38:10
【问题描述】：

目前在 macOS 10.15 上使用 python 3.7，并安装了 MySQL 8.0.19。使用虚拟环境设置在 VScode 中进行开发。我也在 phpmyadmin 中创建了一个本地数据库。无论如何，我想连接到它。脚本：

import pymysql

print("Before")
connection = pymysql.connect(host='localhost',
    user='myUserName', password='myPassword', db='db_name', charset='utf8mb4', 
          cursorclass=pymysql.cursors.DictCursor)
print("After")

当我运行脚本时，执行会无限期挂起。打印“之后”后，我必须退出执行。引用是：

Traceback (most recent call last):
File "connect.py", line 5, in <module>
  user='myUserName', password='myPassword', db='db_name', charset='utf8mb4', 
  cursorclass=pymysql.cursors.DictCursor)
File "/Users/name/Documents/Work/Connection Test/env/lib/python3.7/site- 
  packages/pymysql/__init__.py", line 94, in Connect
  return Connection(*args, **kwargs)
File "/Users/name/Documents/Work/Connection Test/env/lib/python3.7/site- 
  packages/pymysql/connections.py", line 325, in __init__
  self.connect()
File "/Users/name/Documents/Work/Connection Test/env/lib/python3.7/site- 
  packages/pymysql/connections.py", line 598, in connect
  self._get_server_information()
File "/Users/name/Documents/Work/Connection Test/env/lib/python3.7/site- 
  packages/pymysql/connections.py", line 975, in _get_server_information
  packet = self._read_packet()
File "/Users/name/Documents/Work/Connection Test/env/lib/python3.7/site- 
packages/pymysql/connections.py", line 657, in _read_packet
  packet_header = self._read_bytes(4)
File "/Users/name/Documents/Work/Connection Test/env/lib/python3.7/site- 
  packages/pymysql/connections.py", line 691, in _read_bytes
  data = self._rfile.read(num_bytes)
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/
python3.7/socket.py", line 589, in readinto
  return self._sock.recv_into(b)
KeyboardInterrupt

不知道为什么会这样。这里发生了什么？我搜索了大量关于堆栈溢出的问题，但没有一个对我有帮助。

【问题讨论】：

标签： mysql python-3.x visual-studio-code pymysql macos-catalina

【解决方案1】：

通过在 pymysql 连接函数中添加“unix_socket”参数解决了问题。在这里查看答案：pymysql can't connect to MySQL on localhost

import pymysql

print("Before")
conn = pymysql.connect(db='w_dev', user='root', passwd='celebrate', 
unix_socket="/tmp/mysql.sock")
print("After")

这个脚本有效。

【讨论】：