Python: How can I convert string to datetime without knowing the format?

问题

I have a field that comes in as a string and represents a time. Sometimes its in 12 hour, sometimes in 24 hour. Possible values:

1. 8:26
2. 08:26am
3. 13:27

Is there a function that will convert these to time format by being smart about it? Option 1 doesn't have am because its in 24 hour format, while option 2 has a 0 before it and option 3 is obviously in 24 hour format. Is there a function in Python/ a lib that does:

time = func(str_time)

回答1:

super short answer:

from dateutil import parser
parser.parse("8:36pm")
>>>datetime.datetime(2015, 6, 26, 20, 36)
parser.parse("18:36")
>>>datetime.datetime(2015, 6, 26, 18, 36)

Dateutil should be available for your python installation; no need for something large like pandas

If you want to extract the time from the datetime object:

t = parser.parse("18:36").time()

which will give you a time object (if that's of more help to you). Or you can extract individual fields:

dt = parser.parse("18:36")
hours = dt.hour
minute = dt.minute

回答2:

there is one such function in pandas

import pandas as pd
d = pd.to_datetime('<date_string>')

来源：https://stackoverflow.com/questions/31066805/python-how-can-i-convert-string-to-datetime-without-knowing-the-format