Return a list of weekdays, starting with given weekday

Question

My task is to define a function weekdays(weekday) that returns a list of weekdays, starting with the given weekday. It should work like this:

>>> weekdays('Wednesday')
['Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday', 'Monday', 'Tuesday']

So far I've come up with this one:

def weekdays(weekday):
    days = ('Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday',
            'Sunday')
    result = ""
    for day in days:
        if day == weekday:
            result += day
    return result

But this prints the input day only:

>>> weekdays("Sunday")
'Sunday'

What am I doing wrong?

Answer 1

Your result variable is a string and not a list object. Also, it only gets updated one time which is when it is equal to the passed weekday argument.

Here's an implementation:

import calendar

def weekdays(weekday):
    days = [day for day in calendar.day_name]
    for day in days:
        days.insert(0, days.pop())    # add last day as new first day of list           
        if days[0] == weekday:        # if new first day same as weekday then all done
            break       
    return days

Example output:

>>> weekdays("Wednesday")
['Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday', 'Monday', 'Tuesday']
>>> weekdays("Friday")
['Friday', 'Saturday', 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday']
>>> weekdays("Tuesday")
['Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday', 'Monday']