python - How to set conditions for valid dates? -

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• how validate date string format in python? 5 answers
• in python, how check if date valid? 6 answers

i'm reformatting date inputs , part of using try/except function kick out invalid inputs. part of requires me set conditions is/is not valid date. example, 2017 did not have leap year, input '29-02-2017' invalid. example '31/09/2010', since september not have 31st. furthermore, '131/09/2020' invalid because of digits in day. catch drift.

a colleague mentioned created elaborate list conditions each month of year, i'm wondering if there way simplify process.

if want validate format of date (i.e. ensure single format such 01/02/99) can use

from datetime import datetime datetime_object = datetime.strptime(your_date_string_here, '%d/%m/%y') 

this return datetime object if date valid, otherwise fail.

>>> datetime_object = datetime.strptime('29/02/2017', '%d/%m/%y') valueerror: day out of range month 

it fail different formats, e.g.

>>> datetime_object = datetime.strptime('29-02-2017', '%d/%m/%y') traceback (most recent call last): valueerror: time data '29-02-2017' not match format '%d/%m/%y' 

if want able handle multiple formats, take @ dateutil package, can parse date formats.

from dateutil import parser dt = parser.parse(your_date_string_here) 

this throw errors invalid dates, handles different formats e.g.

>>> dt = parser.parse('29-02-2017') traceback (most recent call last): valueerror: day out of range month