Day of week constants with Sunday = 0 in Python

Question

The calendar module has day of week constants beginning with

calendar.MONDAY
Out[60]: 0

However, sometimes one must interface with a system (perhaps written in JavaScript) that uses the convention Sunday = 0. Does Python provide such constants?

Answer 1

There are no such constants in the Python standard library. It is trivial to define your own however:

SUN, MON, TUE, WED, THU, FRI, SAT = range(7)

or, when using Python 3.4 or up, you could use the enum module functional API:

from enum import IntEnum

Weekdays = IntEnum('Weekdays', 'sun mon tue wed thu fri sat', start=0)

weekday == Weekdays.wed

and then you can then also map a weekday integer to an enumeration value by calling the enum.Enum object:

weekday_enum = Weekdays(weekday)

I used 3-letter abbreviations but you are free to use full names if you find that more readable.

Answer 2

I just use this with mydate.isoweekday(), does the job.

def weekday_sun_zero(self, isoweekday):
    return 0 if isoweekday == 7 else isoweekday

Answer 3

hope this helps:

from datetime import datetime
weekdays_dic ={0:'Mon', 1:'Tue',2:'Wed',3:'Thu',4:'Fri',5:'Sat', 6:'SUN'}
print(weekdays_dic[datetime.today().weekday()])