从Python中的文件中删除JSON对象 [英] Remove JSON object from file in Python

问题描述

我不确定json文件是否唯一，但是找不到其他有效的问题/答案.

I'm not sure if my json file is unique but I couldn't find any other question/answers that worked.

我的JSON文件如下:

My JSON file looks like:

{"UserID": "name1", "Timestamp": "1234"}
{"UserID": "name2", "Timestamp": "4321"}
{"UserID": "name3", "Timestamp": "1234"}

python是否有办法从文件中删除整行?

Is there a way for python to delete an entire line from the file?

这是我到目前为止所做的:

This is what I've done so far:

open_file = open("times.json", 'r')
line = open_file.readline()

while line:
    jsonLine = json.loads(line)

    if line['Timestamp'] == '1234':
        del line

open_file.close()

如果时间戳为1234，则我希望它删除整个对象，因此文件将如下所示:

If the timestamp is 1234, I want it to delete the entire object so the file will just look like this:

{"UserID": "name2", "Timestamp": "4321"}

谢谢！

推荐答案

结合jonrsharpe和ajon的建议，而不是在阅读时将其删除，而是将其读入内存，然后再写回.

Combining both jonrsharpe's and ajon's suggestions, instead of deleting it while reading, read it into memory and then write it back.

但是，您可能有一个更轻松的时间来先阅读 json ，然后消除具有匹配元素的行，而不是直接操作文本:

You might however have an easier time to read the jsons first and then eliminate the lines with matched elements, instead of manipulating the text directly:

json_lines = []
with open("times.json", 'r') as open_file:
    for line in open_file.readlines():
        j = json.loads(line)
        if not j['Timestamp'] == '1234':
            json_lines.append(line)

with open("times.json", 'w') as open_file:
    open_file.writelines('\n'.join(json_lines))

与在行中专门查找"TimeStamp":"1234" 的情况相比，此方法在必要时为您提供了多个键/值的更多条件灵活性.

This method gives you more conditional flexibility over multiple keys/values if necessary as opposed to looking specifically for "TimeStamp": "1234" within the line.

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