python模块-pymysql源码分析及其常见使用

D:\soft\python36\Lib\site-packages\pymysql>tree /f
卷 新加卷 的文件夹 PATH 列表
卷序列号为 960E-961E
D:.
│  charset.py
│  connections.py
│  converters.py
│  cursors.py
│  err.py
│  optionfile.py
│  protocol.py
│  times.py
│  util.py
│  _auth.py
│  _compat.py
│  _socketio.py
│  __init__.py
│
├─constants
│  │  CLIENT.py
│  │  COMMAND.py
│  │  CR.py
│  │  ER.py
│  │  FIELD_TYPE.py
│  │  FLAG.py
│  │  SERVER_STATUS.py
│  │  __init__.py
│  │
│  └─__pycache__
│          CLIENT.cpython-36.pyc
│          COMMAND.cpython-36.pyc
│          CR.cpython-36.pyc
│          ER.cpython-36.pyc
│          FIELD_TYPE.cpython-36.pyc
│          FLAG.cpython-36.pyc
│          SERVER_STATUS.cpython-36.pyc
│          __init__.cpython-36.pyc
│
└─__pycache__
        charset.cpython-36.pyc
        connections.cpython-36.pyc
        converters.cpython-36.pyc
        cursors.cpython-36.pyc
        err.cpython-36.pyc
        optionfile.cpython-36.pyc
        protocol.cpython-36.pyc
        times.cpython-36.pyc
        util.cpython-36.pyc
        _auth.cpython-36.pyc
        _compat.cpython-36.pyc
        _socketio.cpython-36.pyc
        __init__.cpython-36.pyc

pymysql源码目录结构

 

# -*- coding: utf-8 -*-
# @Time : 2019/8/14 10:38
# @Author : wangmengmeng
import pymysql
from config.cfg import *


class ConnectDB:
    def __init__(self):
        print('start connecting MySQL...')
        try:
            self.host = host
            self.port = int(port)
            self.username = user_name
            self.password = pwd
            self.db_sf_full = db_auditcenter
        except Exception as e:
            print(e)
        else:
            print("数据库连接成功！")

    def connect(self):
        return pymysql.Connect(host=self.host, port=self.port, user=self.username, passwd=self.password,
                               database=self.db_sf_full, charset='utf8')



if __name__ == '__main__':
    con = ConnectDB()
    # cur = con.connect().cursor() # 返回格式为 元组里嵌套元组
    """
    如：((1002, '3', 'wangmm', '王萌萌', '122', '122', 0, datetime.datetime(2020, 3, 9, 14, 28, 18), None), (12002, '3', 'wangmm', '王萌萌', 'vvv', 'vvv', 0, datetime.datetime(2020, 3, 13, 13, 43, 11), None))
    """
    cur = con.connect().cursor(pymysql.cursors.DictCursor) # 返回格式为 列表里嵌套字典
    """
    如：[{'id': 1002, 'pharmacist_id': '3', 'pharmacist_name': 'wangmm', 'pharmacist_realname': '王萌萌', 'tag': '122', 'tag_py': '122', 'default_flag': 0, 'created_time': datetime.datetime(2020, 3, 9, 14, 28, 18), 'modified_time': None}, {'id': 12002, 'pharmacist_id': '3', 'pharmacist_name': 'wangmm', 'pharmacist_realname': '王萌萌', 'tag': 'vvv', 'tag_py': 'vvv', 'default_flag': 0, 'created_time': datetime.datetime(2020, 3, 13, 13, 43, 11), 'modified_time': None}]
    """
    cur.execute('SELECT * FROM `sf_collect_tag`')
    # print(cur.fetchone())  # 查询一条数据，返回一维元组，若查询结果集有多条，则只会取最上面一条，若没有结果则返回None
    # print(cur.fetchall())  # 查询多条数据，返回二维元组，若没有结果则返回()
    print(cur.fetchmany(2))  # 查询指定条数据