Question

我正在用Python编写一个脚本做一段时间真正的cicle，我如何让我的脚本为每个cicle采用相同的文件abc123.json并修改其中的一些变量？

Answer 1

如果我正确理解你的问题，你想在本地硬盘驱动器上某处读取一个名为abc123.json的文件，该文件可以通过路径访问，并为该json文件修改一个或多个键的值，然后重新写下来。我正在粘贴我前一段时间使用的一些代码的例子，希望它有所帮助

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json_data共享相同的密钥。如果他们不这样做，你的函数将需要弄清楚如何在数据结构之间匹配键。

如何让python写json为每个cicle读写相同的文件

1 个答案: