开发小游戏遇问题：如何判断成员Email是否已分配至Player实例？

你的现有代码没法实现需求，直接判断字符串在file2模块里是无效的——file2只是定义了几个Player变量，Python没法直接从模块中检索实例的属性值。下面是两种可行的解决方式：

方案1：用列表统一管理Player实例 #

先修改file2，把所有Player实例存入一个列表：

# file2.py
player1 = Player("testName1", "test1@gmail.com", "testpwd1")
player2 = Player("testName2", "test2@gmail.com", "testpwd2")
player3 = Player("testName3", "test3@gmail.com", "testpwd3")
player4 = Player("testName4", "test4@gmail.com", "testpwd4")

# 将所有玩家实例汇总到列表中
all_players = [player1, player2, player3, player4]

然后在file1中遍历列表，检查每个实例的邮箱属性：

# file1.py
from file2 import all_players

target_email = "test1@gmail.com"
# 用any()快速判断是否存在匹配的邮箱
email_exists = any(player.email == target_email for player in all_players)

if email_exists:
    print("ok")
else:
    print("not ok")

注意：需要确保你的Player类正确初始化了email属性，类定义示例：

class Player:
    def __init__(self, name, email, password):
        self.name = name
        self.email = email
        self.password = password

方案2：用字典存储（更高效的查找） #

如果玩家数量较多，用字典以邮箱为键存储实例，能实现O(1)时间复杂度的查找：

# file2.py
player1 = Player("testName1", "test1@gmail.com", "testpwd1")
player2 = Player("testName2", "test2@gmail.com", "testpwd2")
player3 = Player("testName3", "test3@gmail.com", "testpwd3")
player4 = Player("testName4", "test4@gmail.com", "testpwd4")

# 以邮箱为键，玩家实例为值构建字典
players_by_email = {
    player1.email: player1,
    player2.email: player2,
    player3.email: player3,
    player4.email: player4
}

在file1中直接检查字典的键是否存在：

# file1.py
from file2 import players_by_email

target_email = "test1@gmail.com"

if target_email in players_by_email:
    print("ok")
else:
    print("not ok")

内容的提问来源于stack exchange，提问作者ENDERastronaute