input: 
  def print_pattern() -> None:
      """Print a number pattern where each row contains numbers from 1 to the row number.
      Example:
      >>> print_pattern()
      1
      12
      123
      1234
      1235
      """
  
output:     for i in range(1, 6):
          for j in range(1, i + 1):
              print(j, end='')
          print()