def paper_doll(text):
    for i in text:
        text1=''
        text1 = i*3
    return text1

paper_doll('tom')

Here via this particular code I want to print every character in the string 'tom' thrice. but when I ran the code only the last character is getting printed thrice. Why is it so?

CodePudding user response：

On the last iteration of the loop, the program:

1. performs text1='' and

2. performs text1 = i*3.

So, regardless of what happened before the last iteration, it is erased in the first step above.

Consider moving initialization (text1='') before the loop.

CodePudding user response：

The variable text1 gets reset every time the code in the for loop runs. So it is set to "ttt", then reset and set to "ooo", then reset and set to "mmm". Only the "mmm" is returned. In order to not have it reset every time the for loop runs, define it outside of the for lop instead:

def paper_doll(text):
    text1=''
    for i in text:
        text1 = i*3
    return text1

paper_doll('tom')

CodePudding user response：

If we rewrite your code using more explicit names, it is equivalent to this:

def paper_doll(text):
    for character in text:
        text1 = character * 3
    return text1

paper_doll('tom')

It does not give the result you want because text1 is overwritten at every loop (therefore giving you only the last character of the string as a triplet).

What you want to do is the following:

def paper_doll(text):
    text1 = ''  # define text1 outside the loop to avoid overwritting it
    for character in text:
        text1 = character * 3
    return text1

paper_doll('tom')

CodePudding user response：

All the answers so far explain why your code does not work as expected and how to fix it. But I suppose you already knew that, since your question is "Why do we need..."

So, why? The string must already exist since you use an "augmented assignment operator", i.e. =. And since it must exist and you don't want to reset it at every iteration, you need to create it outside the loop.