为什么我的 python 脚本执行了 3 次？

Question

我有以下脚本执行了三次，但我不知道为什么#!C:/Python38-32/python.exe#script.pyfrom py_get_data_from_game import mainfrom multiprocessing import Poolimport connect_to_dbimport mysql.connectorfrom mysql.connector import Errorconnection = connect_to_db.connect()user_names = []passwords = []    print('START')  try:    connection = connect_to_db.connect()    if connection.is_connected():        sql_select_Query = "select * from players"        cursor = connection.cursor(dictionary=True)        cursor.execute(sql_select_Query)        records = cursor.fetchall()        for row in records:            user_names.append(row['user_name'])            passwords.append(row['password'])except Error as e:    print("Error while connecting to MySQL", e)finally:    if (connection.is_connected()):        cursor.close()        connection.close()        print("MySQL connection is closed")        if __name__ == '__main__':    pool = Pool(2) # two parallel jobs    results = pool.map(main, zip(user_names, passwords))输出：C:\scripts>script.pySTARTMySQL connection is closedSTARTMySQL connection is closedSTARTMySQL connection is closed

Answer 1

当您使用时multiprocessing，python 需要创建与您的程序碰巧指定的进程一样多的进程，并具有相同的环境（我的意思是imports）。它通过再次运行您的脚本来完成此操作。

为避免同时执行虚假代码，您应该将其放在：

if __name__ == '__main__':