Nested loops: print pattern - triangle of alphabets

Problem: Print the following pattern for a given n (e.g. n=5 below).


A        A
 B      B
  C    C
   D  D
    EE

Solution in Python:

def print_pattern(n):

    """

    Author: Mayur P Srivastava

    n is number of colmns or rows.

    """

    for i in range(n):

        s = ""

        for j in range(i):

            s += " "

        s += chr(ord('A') + i)

        for j in range(-(n-i-1), (n-i-1)):

            s += " "

        s += chr(ord('A') + i)

             

        print s

Concepts learned: nested loops.