input: 
  def print_output_pattern():
      """ Prints a pattern where each line prints numbers from 1 to i, where i is the line number.
      >>> print_output_pattern()
      1
      12
      123
      1234
      12345
      """
  
output:     for i in range(1, 6):
          print(''.join(str(j) for j in range(1, i + 1)))