如何在多字典列表中提取所有元素的email与password值

假设我有如下列表：

[{ "user_id": 1, "firstname": "James", "lastname": "Katarikawe", "email": "jpkatarikawe@gmail.com", "password": "$3cur!ty1" }, { "user_id": 2, "firstname": "Paul", "lastname": "Kayongo", "email": "nserekopaul@gmail.com", "password": "rasengan" }]

请问如何仅打印出该列表中所有元素的email和password值？

嘿，这个需求超简单的！如果你用Python处理这个用户列表，直接遍历每个用户字典，提取对应的email和password字段就行，给你两种常用的实现方式：

方式一：直接打印结果 #

直接循环列表里的每个用户，把需要的字段打印出来：

users = [
    { "user_id": 1, "firstname": "James", "lastname": "Katarikawe", "email": "jpkatarikawe@gmail.com", "password": "$3cur!ty1" },
    { "user_id": 2, "firstname": "Paul", "lastname": "Kayongo", "email": "nserekopaul@gmail.com", "password": "rasengan" }
]

for user in users:
    print(f"邮箱：{user['email']}，密码：{user['password']}")

运行后会输出：

邮箱：jpkatarikawe@gmail.com，密码：$3cur!ty1
邮箱：nserekopaul@gmail.com，密码：rasengan

方式二：生成新的精简列表 #

如果你不想直接打印，而是想要一个只包含email和password的新列表，用列表推导式更高效：

users = [
    { "user_id": 1, "firstname": "James", "lastname": "Katarikawe", "email": "jpkatarikawe@gmail.com", "password": "$3cur!ty1" },
    { "user_id": 2, "firstname": "Paul", "lastname": "Kayongo", "email": "nserekopaul@gmail.com", "password": "rasengan" }
]

# 生成只保留email和password的新列表
filtered_users = [{"email": u["email"], "password": u["password"]} for u in users]
print(filtered_users)

输出结果是：

[{'email': 'jpkatarikawe@gmail.com', 'password': '$3cur!ty1'}, {'email': 'nserekopaul@gmail.com', 'password': 'rasengan'}]

这样不管你是要直接输出还是后续处理，都能满足需求啦～

内容的提问来源于stack exchange，提问作者myrdstom