json.dump 没报错但打开json文件没写进去

import json
filename = 'user_fav_num.json'

def get_num():
    num = input("What's your favrotite number? ")
    print("We will remember it next time you visit!")
    return str(num)

try:
    with open(filename) as f:
        user_fav_num = json.load(f)
except FileNotFoundError:
    user_fav_num = get_num()
    with open(filename, 'w') as f:
        json.dump = (user_fav_num, f)
else:
    print(f"Your favorite number is {user_fav_num}, isnt it?")

把15行的 = 号去掉即可。

import json
filename = 'user_fav_num.json'
 
def get_num():
    num = input("What's your favrotite number? ")
    print("We will remember it next time you visit!")
    return str(num)
 
try:
    with open(filename) as f:
        user_fav_num = json.load(f)
except FileNotFoundError:
    user_fav_num = get_num()
    with open(filename, 'w') as f:
        json.dump(user_fav_num, f)
else:
    print(f"Your favorite number is {user_fav_num}, isnt it?")