python - 存储数据

1. 使用json.dump()和json.load()

将列表保存到numbers.json

import json

numbers = [2, 3, 5, 7, 11, 13]

filename = 'E:/jacob/myJupyter/data/numbers.json'
with open(filename, 'w') as f:
    json.dump(numbers, f)

将numbers.json读取到内存中

import json

filename = 'E:/jacob/myJupyter/data/numbers.json'
with open(filename) as f:
    numbers = json.load(f)
    
for number in numbers:
    print(number)

2. 保存和读取用户生成的数据

import json

def get_stored_username():
    """如果用户存储了用户名，就获取它"""
    filename = 'E:/jacob/myJupyter/data/username.json'
    try:
        with open(filename) as f:
            username = json.load(f)
    except FileNotFoundError:
        return None
    else:
        return username

def get_new_username():
    """"提示用户输入用户名，并存储它"""
    username = input("Whar is your name? ")
    filename = 'E:/jacob/myJupyter/data/username.json'
    with open(filename, 'w') as f:
        json.dump(username, f)
    return username

def greet_user():
    """问候用户，并指出其名字"""
    username = get_stored_username()
    if username:
        print(f"Welcome back, {username}!")
    else:
        username = get_new_username()
        print(f"We will remember you when you come back, {username}!")

greet_user()