Joining words together with a comma, and "and"

Question

I'm working through 'Automate the Boring Stuff with Python'. I can't figure out how to remove the final output comma from the program below. The goal is to keep prompting the user to input values, which are then printed out in a list, with "and" inserted before the end. The output should look something like this:

apples, bananas, tofu, and cats 

Mine looks like this:

apples, bananas, tofu, and cats, 

That last comma is driving me NUTS.

def lister():     listed = []     while True:         print('type what you want to be listed or type nothing to exit')         inputted = input()         if inputted == '':             break         else:             listed.append(inputted+',')     listed.insert(-1, 'and')     for i in listed:         print(i, end=' ') lister() 

Answer 1

You can avoid adding commas to each string in the list by deferring the formatting to print time. Join all the items excluding the last on ', ', then use formatting to insert the joined string with the last item conjuncted by and:

listed.append(inputed) ... print('{}, and {}'.format(', '.join(listed[:-1]), listed[-1])) 

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Demo:

>>> listed = ['a', 'b', 'c', 'd'] >>> print('{}, and {}'.format(', '.join(listed[:-1]), listed[-1])) a, b, c, and d