How to create a function to loop through a string list in python

Question

Hi lets say I have a list containing these string values:

food = ['apples', 'bananas', 'tofu', 'pork']

I'm tasked to write a function that takes the list value as an argument and returns a string with all the items separated by a comma and a space, with "and" inserted before the last item

My solution to this was:

def formatList(food):
    result = ""
    for idx in food: 
        result += idx + "," + " "
    return result

if I print this called function the result is:

print(formatList(food))
>> apples, bananas, tofu, pork,

The intended output is supposed to be:

print(formatList(food))
>> 'apples, bananas, tofu, and pork'

How can i fix this?

*How can I fix this?* - By iterating until the one-before-last element and adding the last one separately... — Tomerikoo, Sep 24 '20 at 13:04
hay there, please consider selecting an answer if it helps you !! :) — luckyCasualGuy, Sep 24 '20 at 14:52

score 2 · Accepted Answer · answered Sep 24 '20 at 13:03

2

food = ['apples', 'bananas', 'tofu', 'pork']

def concat(food):
    return ", ".join(food[:-1]) + " and " + food[-1]

print(concat(food))
## output 'apples, bananas, tofu and pork'

answered Sep 24 '20 at 13:03

luckyCasualGuy

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If you want the explanation i will give you – luckyCasualGuy Sep 24 '20 at 13:05

score 0 · Answer 2 · answered Sep 24 '20 at 13:05

It can be done using the index of list instead of the content of list for the for loop:

def formatList(food):
    result = ""
    for i in range(len(food)):
        if i == len(food)-1:
            result += f"and {food[i]}"
        else:
            result += f"{food[i]}, "
    return result

How to create a function to loop through a string list in python

2 Answers2