''' Purpose: introduce nested looping.
        for a user-supplied n, loop n times, where on the ith iteration
        the integers from 0 to i are printed out.
'''

import time

# get n
reply = input( 'Enter number: ' )
n = int( reply )

# performed the repeated printing of a number series
for i in range( 0, n ) :
    # print a line of the form i: 0 1 2 ... i
    print( i , ":", end=" ")

    for j in range( 0 , i + 1 ):
        print ( j, end= " " ) # Remember the end="" just puts it all on one line
    print()
# General thing about nested for loops:
    # For the current i we are on, it will finish
    # the j loop for that given i, move onto the next
    # i in the range and continue that cycle until
    # we reach the end of our i range.
# Where can we put the new line character to separate
# the i values?
    # Keep indentation in mind!
    # We put the print() after we printed out all the j
    # values for the i we are curerrently on and THEN
    # print out a line after we are done with that i value.

# Right now with this single for loop, we're just
# printing out values of i. (The output is just the
# left hand numbers in output.
# But we also want to have another way to print
# out each number counting up to i with each i.
# How do we do that?