如何使python写入json读取和写入每个cicle的相同文件

Question

我正在用Python编写一个脚本，而不是真正的cicle，我怎样才能让我的脚本对每个cicle采用相同的文件abc123.json并修改一些变量在里面？

Answer 1

如果我正确理解你的问题，你需要读取一个名为abc123.json的文件，该文件位于可通过路径访问的本地硬盘上，并修改该json文件的一个键（或多个）的值，然后重新-写下来。 我粘贴的一些代码，我使用了前一段时间，希望一个例子可以帮助

import json 
from collections import OrderedDict 
from os import path 

def change_json(file_location, data): 
    with open(file_location, 'r+') as json_file: 
     # I use OrderedDict to keep the same order of key/values in the source file 
     json_from_file = json.load(json_file, object_pairs_hook=OrderedDict) 
     for key in json_from_file: 
      # make modifications here 
      json_from_file[key] = data[key] 
     print(json_from_file) 
     # rewind to top of the file 
     json_file.seek(0) 
     # sort_keys keeps the same order of the dict keys to put back to the file 
     json.dump(json_from_file, json_file, indent=4, sort_keys=False) 
     # just in case your new data is smaller than the older 
     json_file.truncate() 

# File name 
file_to_change = 'abc123.json' 
# File Path (if file is not in script's current working directory. Note the windows style of paths 
path_to_file = 'C:\\test' 

# here we build the full file path 
file_full_path = path.join(path_to_file, file_to_change) 

#Simple json that matches what I want to change in the file 
json_data = {'key1': 'value 1'} 
while 1: 
    change_json(file_full_path, json_data) 
    # let's check if we changed that value now 
    with open(file_full_path, 'r') as f: 
     if 'value 1' in json.load(f)['key1']: 
      print('yay') 
      break 
     else: 
      print('nay') 
      # do some other stuff 

观察：上面的代码假定您的文件和两个json_data共享同一个密钥。如果他们没有，你的函数将需要弄清楚如何匹配数据结构之间的键。