script to swap case in python

Question

this script is supposed to swap case in words but the result is really weird and doesn't make sense

def swap_case(s):
for i in range(len(s)):
    if s[i].islower():
        s= s.replace(s[i],s[i].upper())
    elif s[i].isupper():
        s= s.replace(s[i],s[i].lower())
    else:
        pass

example

What is some output that is abnormal in your opinion so we can troubleshoot effectively? — Treatybreaker, Apr 29 '20 at 16:52
give sample strings, are they all uppercase or lowercase, or mixed upper and lower case words? — yoss, Apr 29 '20 at 16:54
`replace` replaces all occurences of a char in the string, so it will change the ones you already changed or would have changed later... You should build a list of your changed chars, and `join` them at the end. — Thierry Lathuille, Apr 29 '20 at 16:58

score 4 · Accepted Answer · answered Apr 29 '20 at 17:08

4

First of all consider using inbuild swapcase function Otherwise, you can use join function

E.g.

s = "hELLO wORLD"
# inbuilt
print(s.swapcase())
# join
print(''.join([ss.lower() if ss.isupper() else ss.upper() for ss in s]))

which gives you

answered Apr 29 '20 at 17:08

Jackson

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score 3 · Answer 2 · answered Apr 29 '20 at 16:58

3

You're going through each letter in the string, then replacing all instances of that letter. That means that if there's an even amount of a letter, the case won't be changed.

Also, a method, swapcase, already exists for this.

>>> 'Hello World!'.swapcase()
'hELLO wORLD!'

answered Apr 29 '20 at 16:58

duckboycool

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I was thinking of this... but reading *this script is supposed to change lower case **words** into upper case and vice versa* (emphasis mine) - I'm not sure it's correct - the description and the actual attempted code are somewhat contradictory... – Jon Clements Apr 29 '20 at 17:00
@JonClements I doubt they'd be iterating through each letter in the word and trying to replace if that were the case. I guess we'll see what they say though. – duckboycool Apr 29 '20 at 17:04

score 0 · Answer 3 · answered Apr 29 '20 at 17:09

0

Here is the solution for your problem-->

def swap_case(s):
    k=''
    for i in range(len(s)):
        if s[i].islower():
            k+=s[i].upper()
        elif s[i].isupper():
            k+=s[i].lower()
        else:
            pass
    print(k)

answered Apr 29 '20 at 17:09

MrFamousKK

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2

It is more efficient to build a list and `join` it at the end – Thierry Lathuille Apr 29 '20 at 17:11
it works but it should be like this to work perfectly . thanks :) – Arian Apr 29 '20 at 17:13
def swap_case(s): k='' for i in range(len(s)): if s[i].islower(): k+=s[i].upper() elif s[i].isupper(): k+=s[i].lower() else: k+=s[i] print(k) swap_case("Hello World") – Arian Apr 29 '20 at 17:14
Yes. I just thought i would return him the function which is a bit less complicated and he would understand it easily. Your suggestion is very good ! – MrFamousKK Apr 29 '20 at 17:14

score 0 · Answer 4 · answered Jul 19 '21 at 11:50

Solution with Python

Case Swapping can be achieve using a python built-in function called swapcase if you want to do this manually then here is the code.

result = ''
    for element in (s):
        if element.isupper():
            result += element.lower()
        else:
            result += element.upper()  
        print(result)

script to swap case in python

4 Answers4

Solution with Python

Linked