python how to uppercase some characters in string

Question

Here is what I want to do but doesn\'t work:

mystring = \"hello world\"
toUpper = [\'a\', \'e\', \'i\', \'o\', \'u\', \'y\']
array = list(mystring)

for c in arr         


        

Answer 1

You are not making changes to the original list. You are making changes only to the loop variable c. As a workaround you can try using enumerate.

mystring = "hello world"
toUpper = ['a', 'e', 'i', 'o', 'u', 'y']
array = list(mystring)

for i,c in enumerate(array):
    if c in toUpper:
        array[i] = c.upper()

print(array) 

Output

['h', 'E', 'l', 'l', 'O', ' ', 'w', 'O', 'r', 'l', 'd']

Note: If you want hEllO wOrld as the answer, you might as well use join as in ''.join(array)