input: Write a function to print a pattern of asterisks based on the input number of rows.
  assert printPattern(3) == None # Output should be:
  # *
  # * *
  # * * *
  assert printPattern(4) == None # Output should be:
  # *
  # * *
  # * * *
  # * * * *
  assert printPattern(1) == None # Output should be:
  # *
output: def printPattern(n):
      for i in range(1, n+1):
          print('* ' * i)