Iterate over a String.
For loop version:
str = 'Python' for letter in str: print letter
While loop version:
str = 'Python' i = 0 while i < len(str): print str[i] i = i+1
In the for-loop we don’t need the index variable to iterate over the string, while in the while loop we use the variable i as the index for the string. We first initialize the variable i and set it to 0. Then, every time when the loop is executed, the variable i is increased by 1 until it reaches the last index.