存储数据

1、使用json.dump()和json.load()

import json

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

filename = 'numbers.json'
with open(filename, 'w') as f_obj:
    json.dump(numbers, f_obj)

import json

filename = 'numbers.json'
with open(filename) as f_obj:
    numbers = json.load(f_obj)

print(numbers)

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

2、保存和读取用户生成的数据

import json

username = input("what is your name? ")

filename = 'username.json'
with open(filename, 'w') as f_obj:
    json.dump(username, f_obj)
    print("We'll remember you when you come back, " + username + "!")

what is your name? jian
We'll remember you when you come back, jian!

import json

filename = 'username.json'
with open(filename) as f_obj:
    username = json.load(f_obj)
    print("Welcome back, " + username + "!")

Welcome back, jian!

import json

# 如果以前存储了用户名，就加载它
# 否则，就提示用户输入用户名并存储它
filename = 'username.json'
try:
    with open(filename) as f_obj:
        username = json.load(f_obj)
except FileNotFoundError:
    username = input("What is your name? ")
    with open(filename, 'w') as f_obj:
        json.dump(username, f_obj)
        print("We'll remember you when you come back, " + username + "!")
else:
    print("Welcome back, " + username + "!")

Welcome back, jian!