【后端】【语言】【python】python常见操作

roman_日积跬步-终至千里2024-09-25 23:09

文章目录

- - [1. List 操作](#1. List 操作)
  - [2. JSON 操作](#2. JSON 操作)
  - [3. Dict 操作](#3. Dict 操作)

下面是分别演示 list、json、dict 操作

1. List 操作

python 复制代码

my_list=[]
# List 操作示例
my_list = [1, 2, 3, "apple", True]

# 添加元素
my_list.append("new item")  # [1, 2, 3, "apple", True, "new item"]

# 修改元素
my_list[1] = "banana"  # [1, "banana", 3, "apple", True, "new item"]

# 删除元素
my_list.remove("banana")  # [1, 3, "apple", True, "new item"]

# 列表长度
length = len(my_list)  # 5

# 遍历列表
for item in my_list:
    print(item)

2. JSON 操作

python 复制代码

import json

# 字典转 JSON 字符串
my_dict = {"name": "Alice", "age": 30, "is_student": False}
json_str = json.dumps(my_dict, indent=4, ensure_ascii=False)  # '{"name": "Alice", "age": 30, "is_student": false}'
print(json_str)

# JSON 字符串转字典
json_str = '{"name": "Alice", "age": 30, "is_student": false}'
my_dict = json.loads(json_str)  # {'name': 'Alice', 'age': 30, 'is_student': False}
print(my_dict)

3. Dict 操作

python 复制代码

# Dict 操作示例
my_dict = {"name": "Alice", "age": 30, "is_student": False}

# 访问元素
name = my_dict["name"]  # "Alice"

# 修改元素
my_dict["age"] = 31  # {"name": "Alice", "age": 31, "is_student": False}

# 添加键值对
my_dict["city"] = "New York"  # {"name": "Alice", "age": 31, "is_student": False, "city": "New York"}

# 删除键值对
del my_dict["is_student"]  # {"name": "Alice", "age": 31, "city": "New York"}

# 遍历字典
for key, value in my_dict.items():
    print(f"{key}: {value}")