how to replace characters from a string python code example

Example 1: python replace letters in string

my_text = 'Aello world'
my_text = my_text.replace(my_text[0], 'H')
print (my_text)

Example 2: replace character in string python

>>> x = 'xpple bxnxnx cherry'
>>> a = x.replace(x,a)  # replaces x with a
'apple banana cherry'

>>> first_a = x.replace(x,a,1)  # only replaces first a
'apple bxnxnx cherry'