Python How to capitalize nth letter of a string

Question

I tried this: Capitalize a string. Can anybody provide a simple script/snippet for guideline?

Python documentation has capitalize() function which makes first letter capital. I want something like make_nth_letter_cap(str, n).

score 21 · Accepted Answer · answered Apr 07 '13 at 02:22

21

Capitalize n-th character and lowercase the rest as capitalize() does:

def capitalize_nth(s, n):
    return s[:n].lower() + s[n:].capitalize()

answered Apr 07 '13 at 02:22

jfs

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score 14 · Answer 2 · answered Apr 07 '13 at 01:56

14

my_string[:n] + my_string[n].upper() + my_string[n + 1:]

Or a more efficient version that isn't a Schlemiel the Painter's algorithm:

''.join([my_string[:n], my_string[n].upper(), my_string[n + 1:]])

answered Apr 07 '13 at 01:56

icktoofay

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Here is some more information regarding string concatenation in python https://stackoverflow.com/questions/12169839/which-is-the-preferred-way-to-concatenate-a-string-in-python – casol Jan 03 '19 at 20:46
in your case N=3 and therefore we can't be sure what implementation O(N) or O(N*N) would be more "efficient" (for such a small N). I don't know what is more efficient `''.join([a, b, c])` or `a+b+c` (or is it even worth it to worry about the time it takes to concatenate a couple of string relative to other parts in a codebase). – jfs May 02 '19 at 19:29

cppcoder · Answer 3 · 2013-04-08T04:46:04.080

1

x = "string"
y = x[:3] + x[3].swapcase() + x[4:]

Output

strIng

Code

Keep in mind that swapcase will invert the case whether it is lower or upper.
I used this just to show an alternate way.

edited Apr 08 '13 at 04:46

answered Apr 07 '13 at 02:00

cppcoder

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I added a note below my answer – cppcoder Apr 08 '13 at 04:46

score 0 · Answer 4 · answered Aug 29 '18 at 18:53

I know it's an old topic but this might be useful to someone in the future:

def myfunc(str, nth):
new_str = '' #empty string to hold new modified string
for i,l in enumerate(str): # enumerate returns both, index numbers and objects
    if i % nth == 0: # if index number % nth == 0 (even number)
        new_str += l.upper() # add an upper cased letter to the new_str
    else: # if index number nth
        new_str += l # add the other letters to new_str as they are
return new_str # returns the string new_str

score 0 · Answer 5 · answered Jun 28 '19 at 06:58

0

A simplified answer would be:

    def make_nth_letter_capital(word, n):
        return word[:n].capitalize() + word[n:].capitalize()

answered Jun 28 '19 at 06:58

roopali k

1

Could you add short explanation what this code does – Cray Jun 28 '19 at 07:21

gokulrejithkumar · Answer 6 · 2020-08-08T11:15:16.647

0

def capitalize_n(string, n):
return string[:n] + string[n].capitalize() + string[n+1:]

This works perfect

edited Aug 08 '20 at 11:15

answered Aug 01 '19 at 13:27

gokulrejithkumar

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score 0 · Answer 7 · answered Sep 14 '20 at 13:33

You can use:

def capitalize_nth(text, pos):
    before_nth = text[:pos]
    n = text[pos].upper()
    new_pos = pos+1
    after_nth = text[new_pos:]
    word = before_nth + n + after_nth
    print(word)

capitalize_nth('McDonalds', 6)

The outcome is:

'McDonaLds'

I think this is the simplest among every answer up there...

Python How to capitalize nth letter of a string

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