Regex operation to modify a string

Question

At the moment I have a string similar to:

mytime = '143456.45674'

That string is giving time in :

%HH%MM:%SS . something else

I am only interested in HH:MM:SS format so I could do:

mynewTime = mytime[0:2]+":"+mytime[2:4]+":"+mytime[4:6]
'14:34:56'

It is a bit ugly and I was wondering if there was a more elegant/efficient way of doing it. Regex perhaps?

Answer 1

Looks like you're looking for a combination of strptime and strftime :

import datetime

mytime = '143456.45674'

ts = datetime.datetime.strptime(mytime, '%H%M%S.%f')
print ts.strftime('%H:%M:%S')

# 14:34:56

Answer 2

一个有趣的正则表达式版本:)

re.sub(r"(\d{2})(\d{2})(\d{2})\.\d+", r"\1:\2:\3", mytime)

Answer 3

If you want to do it in regex

>>> import re
>>> val=re.sub(r"\..*$", "", "143456.45674")
>>> re.sub(r"(?<=\d)(?=(\d{2})+$)", ":", val )
'14:34:56'