python 从入门到实践 练习 10-11喜欢的数 练习 10-12记住喜欢的数
练习 10-11 喜欢的数
编写一个程序,提示用户输入喜欢的数,并使用 json.dump() 将这个数存储到文件中。再编写一个程序,从文件中读取这个值,并打印如下所示的消息。
I know your favorite number!It's _________.
1 import json
2
3 filename = 'number.json'
4
5 with open(filename, 'w') as f:
6 number = input("Please enter your favorite number: ")
7 number = int(number)
8 json.dump(number, f)
1 import json
2
3 filename = 'number.json'
4
5 with open(filename) as f:
6 number = json.load(f)
7 print(f"I know your favorite number! It's {number}")
练习 10-12 记住喜欢的数
将练习10-11中的程序合二为一。如果存储了用户喜欢的数,就像用户显示它,否则提示用户输入喜欢的数并将其存储到文件中。运行这个程序两次,看看它能否像预期的那样工作。
1 import json
2
3 filename = 'favorite_number.json'
4
5 try:
6 with open(filename) as f:
7 number = json.load(f)
8 except FileNotFoundError:
9 with open(filename, 'w') as f:
10 number = input("Please enter your favorite number: ")
11 number = int(number)
12 json.dump(number, f)
13 print("We will remeber your favorite number.")
14 else:
15 print(f"I know your favorite number. It's {number}")