python3线程池

背景

由于不同乙方对服务商业务接口字段理解不一致，导致线上上千万数据量数据存在问题，为了修复数据，通过Python脚本进行修改

目的

记录与分享

知识点

Python3、线程池、pymysql、CSV文件 *** 作、requests

拓展

当我们程序在使用到线程、进程或协程的时候，以下三个知识点可以先做个基本认知，自行百度吧

CPU密集型、IO密集型、GIL全局解释器锁

库

pip3 install requests

pip3 install pymysql

流程

 

实现代码

# -*- coding:utf-8 -*-
# @FileName:grade_update.py
# @Author  :YYQ
# @Desc    :在一台超级计算机上运行过的牛逼Python代码
import time
import requests
import pymysql
from projectPath import path
import queue
from concurrent.futures import ThreadPoolExecutor


class BoundedThreadPoolExecutor(ThreadPoolExecutor):
    def __init__(self, max_workers=None, thread_name_prefix=''):
        super().__init__(max_workers, thread_name_prefix)
        self._work_queue = queue.Queue(self._max_workers * 2)  # 队列大小为最大线程数的两倍


gradeId = [4303, 4304, 1000926, 1000927]


def writ_mysql():
    """
    :return:
    """
    return pymysql.connect(host="localhost",
                           port=3306,
                           user="admin",
                           password="admin",
                           database="test"
                           )


def oprationdb(grade_id, member_id):
    db = writ_mysql()
    try:
        cursor = db.cursor()
        sql = f"UPDATE `t_m_member_grade` SET `current_grade_id`={grade_id}, `modified` =now() WHERE `member_id`={member_id};"
        cursor.execute(sql)
        db.commit()
        print(f"提交的SQL->{sql}")
    except pymysql.Error as e:
        db.rollback()
        print("DB数据库异常：", e)
    db.close()
    return True


def interface(rows, thead):
    print(f"处理数据行数--->{thead}----数据--->{rows}")
    try:
        # url = "http://localhost:8080/api/elc-data/Tmall/bindQuery"
        # body = {
        #     "nickname": str(rows[0]),
        #     "seller_name": "xxxxx官方旗舰店",
        #     "mobile": "111"
        # }
        # heade={"Content-Type": "application/x-www-form-urlencoded"}
        # res = requests.post(url=url, data=body,headers=heade)
        # result = res.json()
        # if result["data"]["status"] in [1, 2]:
        #     grade = result["data"]["member"]["level"]
        #     grade_id = gradeId[grade]
        #     oprationdb(grade_id=grade_id, member_id=rows[1])
        #     return True
        return True
    except Exception as e:
        print(f"调用异常:{e}")


def update_data():
    import csv
    # db = writ_mysql()
    # 使用csv的reader()方法，创建一个reader对象
    MAX_WORKERS = 5
    with BoundedThreadPoolExecutor(MAX_WORKERS) as pool:
        with open(path + '/file/result2_colu.csv', 'r', newline='', encoding='utf-8') as f:
            obj_list = []
            seq_done = set()
            reader = csv.reader(f)
            n = 0
            for row in reader:
                n += 1
                # 遍历reader对象的每一行
                try:
                    pool.submit(interface, rows=row, thead=n)
                except Exception as e:
                    print(f"解析结果出错：{e}")
    # db.close()
    pool.shutdown()


if __name__ == '__main__':
    update_data()

解释

引入线程池库

from concurrent.futures import ThreadPoolExecutor

重写ThreadPoolExecutor类，用来定义有界队列，作用是为了在处理大数据量任务的时候不会让内存持续增加，导致服务器内存溢出

pool.submit(interface, rows=row, thead=n)

提交任务，interface调用的函数，rows、thead为interface()函数的入参

任务持续提交，线程池通过 MAX_WORKERS 定义的线程数持续消费

说明，像这种I/O密集型的 *** 作脚本适合使用多线程，如果是CPU密集型建议使用进行，根据机器核数进行配置