replace character in string python

1my_text = 'Aello world'
2my_text = my_text.replace(my_text[0], 'H')
3print (my_text)

1
2# Python3 program to demonstrate the  
3# use of replace() method   
4  
5string = "geeks for geeks geeks geeks geeks" 
6   
7# Prints the string by replacing geeks by Geeks  
8print(string.replace("geeks", "Geeks"))  
9  
10# Prints the string by replacing only 3 occurrence of Geeks   
11print(string.replace("geeks", "GeeksforGeeks", 3)) 

1>>> x = 'xpple bxnxnx cherry'
2>>> a = x.replace(x,a)  # replaces x with a
3'apple banana cherry'
4
5>>> first_a = x.replace(x,a,1)  # only replaces first a
6'apple bxnxnx cherry'

1# string.replace(old, new, count),  no import is necessary
2text = "Apples taste Good."
3print(text.replace('Apples', 'Bananas'))          # use .replace() on a variable
4Bananas taste Good.          <---- Output
5
6print("Have a Bad Day!".replace("Bad","Good"))    # Use .replace() on a string
7Have a Good Day!             <----- Output
8
9print("Mom is happy!".replace("Mom","Dad").replace("happy","angry"))  #Use many times
10Dad is angry!                <----- Output

1mytext = 'Hello Zorld'
2mytext = mytext.replace('Z', 'W')
3print mytext,

1>>> s = list("Hello zorld")
2>>> s
3['H', 'e', 'l', 'l', 'o', ' ', 'z', 'o', 'r', 'l', 'd']
4>>> s[6] = 'W'
5>>> s
6['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
7>>> "".join(s)
8'Hello World'