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:

Answer 1

def weekdays(day):
    days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
    i=days.index(day) # get the index of the selected day
    d1=days[i:] #get the list from an including this index
    d1.extend(days[:i]) # append the list form the beginning to this index
    return d1

And if you want to test that it works:

def test_weekdays():
    days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
    for day in days:
        print weekdays(day)

Answer 2

Hmm, you are currently only searching for the given weekday and set as result :) You can use the slice ability in python list to do this:

result = days[days.index(weekday):] + days[:days.index(weekdays)]

Answer 3

You don't need to hardcode array of weekdays. It's already available in calendar module.

import calendar as cal

def weekdays(weekday):
    start = [d for d in cal.day_name].index(weekday)
    return [cal.day_name[(i+start) % 7] for i in range(7)]

Answer 4

Here's more what you want:

def weekdays(weekday):
    days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
    index = days.index(weekday)
    return (days + days)[index:index+7]

Answer 5

Every time you run the for loop, the day variable changes. So day is equal to your input only once. Using "Sunday" as input, it first checked if Monday = Sunday, then if Tuesday = Sunday, then if Wednesday = Sunday, until it finally found that Sunday = Sunday and returned Sunday.

Answer 6

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']