Date time error in Python

Question

I'm trying to learn the functions of Python but there is one thing I came across which I cannot figure out.

calculated_time = '2014.03.08 11:43:12'
>>> calculated_time = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
>>> print calculated_time
    2017-09-22 15:59:34

Now when I run:

cmpDate = datetime.strptime(calculated_time, '%Y.%m.%d %H:%M:%S')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/_strptime.py", line 332, in _strptime
(data_string, format))
ValueError: time data '2017-09-22 16:35:12' does not match format'%Y.%m.%d %H:%M:%S'

I can't understand why, if I directly pass this date then it is running but when I pass it after storing in a variable then I've got an error.

You're looking for %Y.%m.%d and providing it %Y-%m-%d which doesn't match... — Jon Clements
– Jon Clements, Commented Sep 22, 2017 at 13:02

Eric Duminil · Accepted Answer · 2017-09-22 13:02:35Z

They are not the same formats :

'%Y.%m.%d %H:%M:%S'
'%Y-%m-%d %H:%M:%S'

Notice the different separators between year, month and day? You need to use a consistent datetime format between strftime and strptime.

As an example :

>>> from datetime import datetime
>>> datetime.now().strftime("%Y-%m-%d %H:%M:%S")
'2017-09-22 15:06:51'
>>> datetime.strptime(datetime.now().strftime("%Y-%m-%d %H:%M:%S"), "%Y-%m-%d %H:%M:%S")
datetime.datetime(2017, 9, 22, 15, 3, 52)
>>> datetime.strptime(datetime.now().strftime("%Y-%m-%d %H:%M:%S"), "%Y.%m.%d %H:%M:%S")

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/media/steam/anaconda3/lib/python3.6/_strptime.py", line 565, in _strptime_datetime
    tt, fraction = _strptime(data_string, format)
  File "/media/steam/anaconda3/lib/python3.6/_strptime.py", line 362, in _strptime
    (data_string, format))
ValueError: time data '2017-09-22 15:03:57' does not match format '%Y.%m.%d %H:%M:%S'
>>> datetime.now().strftime("%Y.%m.%d %H:%M:%S")
'2017.09.22 15:06:55'
>>> datetime.strptime(datetime.now().strftime("%Y.%m.%d %H:%M:%S"), "%Y.%m.%d %H:%M:%S")
datetime.datetime(2017, 9, 22, 15, 4, 3)

shrewmouse · Accepted Answer · 2017-09-22 13:09:26Z

0

because you specified a format of '%Y.%m.%d %H:%M:%S' but you put '-' between the date elements instead of "."

edited Sep 22, 2017 at 13:09

answered Sep 22, 2017 at 13:02

shrewmouse

6,1403 gold badges42 silver badges48 bronze badges

Collectives™ on Stack Overflow

Date time error in Python

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related