input: Write a function to print the following output pattern based on the given input. If the input is an integer greater than 0, the function should print a right-angled triangle where each row contains numbers from 1 to the current row number. The function should return None.
  
  assert print_pattern(5)==None
  assert print_pattern(3)==None
  assert print_pattern(1)==None
  assert print_pattern(-1)==None
output: def print_pattern(n):
      if n > 0:
          for i in range(1, n + 1):
              for j in range(1, i + 1):
                  print(j, end='')
              print()
      return None