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Python

Posted by Mikaela Land
.a{fill-rule:evenodd;}techdegree
Mikaela Land
Python Web Development Techdegree Student 2,324 Points

Creating commas in string but leaving out one comma transferred from list

So I'm creating a function that takes a list and turns it into a string. I want commas and place the word "and" at the end, which I got working. However I want a spot between tofu and cats where there is no comma, which is my dilemma. Here's the code so far:

#Write a function that takes list value as an argument and return a string

spam = ['apples', 'bananas', 'tofu', 'cats']

def comma_code (comma):
    comma.insert (-1, 'and')
    join_string = ",  ".join(comma)
    print (join_string)
print (comma_code(spam))

Yes this is from "How to Automate the Boring Stuff"

1 Answer

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

I'm assuming you mean between "and" and "cats" (instead of "tofu" and "cats"). One way would be to rsplit (right-split) on the final comma and then rejoin with a blank separator:

    join_string = "".join(", ".join(comma).rsplit(",", 1))

If you want to eliminate both the commas before and after "and", change that 1 to a 2.

Mikaela Land
.a{fill-rule:evenodd;}techdegree
Mikaela Land
Python Web Development Techdegree Student 2,324 Points

I'm unfamiliar with rsplit... so it puts in a comma and what's the 1 for?

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

It's like "split" but working right-to-left, and it's to take out the comma(s). The 1 (or 2) is the limit on how many splits to perform.