使用python从日志文件计算增量时间

我一直在试图从日志文件中查找第一个和最后一个时间戳的增量

下面是日志文件的一部分

[2020-07-31 15:49:22,015][SRC.Env][I]:Reading 
[2020-07-31 15:49:22,015][SRC.Env][I]:Finished Initilization 
[2020-07-31 15:49:22,052][SRC][I]:Creating link
[2020-07-31 15:49:22,053][SRC][I]:Starting
.
.
.
[2020-08-03 09:17:29,351][SRC.Upload][I]:Finished

以下是我迄今为止所做的工作

import re
from dateutil import parser

with open('run.log') as run_log:
  times = [re.findall(r'\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2},\d{3}',
      line) for line in run_log.readlines() if 'SRC' in line]
print(times)

time_delta = parser.parse(times[-1]) - parser.parse(times[0])
print(time_delta)

当我打印时间时，它似乎显示了所有的时间（如预期的那样）

['2020-07-31 15:49:22011']，['2020-07-31 15:49:22015']，…['2020-08-03 09:17:29351']

然而，当我试图将第一次减到最后一次时，我收到了以下错误

    return DEFAULTPARSER.parse(timestr, **kwargs)
  File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\site-packages\dateutil\parser\_parser.py", line 646, in parse
    res, skipped_tokens = self._parse(timestr, **kwargs)
  File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\site-packages\dateutil\parser\_parser.py", line 725, in _parse
    l = _timelex.split(timestr)         # Splits the timestr into tokens
  File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\site-packages\dateutil\parser\_parser.py", line 207, in split
    return list(cls(s))
  File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\site-packages\dateutil\parser\_parser.py", line 76, in __init__
    '{itype}'.format(itype=instream.__class__.__name__))
TypeError: Parser must be a string or character stream, not list

大约两个月前，我决定学习如何编写代码，所以任何帮助都将真正有助于我的进步。谢谢：）

问题是返回一个

列表

您可以使用
re.findall（pattern，s）[0]

import re
from dateutil import parser

with open('run.log') as run_log:
    times = [re.findall(r'\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2},\d{3}',
                        line)[0] for line in run_log.readlines() if 'SRC' in line]
print(times)

time_delta = parser.parse(times[-1]) - parser.parse(times[0])
print(time_delta)

输出：

['2020-07-31 15:49:22,015', '2020-07-31 15:49:22,015', '2020-07-31 15:49:22,052', '2020-07-31 15:49:22,053', '2020-08-03 09:17:29,351']
2 days, 17:28:07.336000