input: Write a function to print the following output pattern based on the number of rows specified. If the input number is 0, then print an empty line.
  assert pattern_print(5)==for i in range(1,6):     for j in range(1,i+1):         print(j, end="")     print()
  assert pattern_print(0)==""
  assert pattern_print(3)==for i in range(1,4):     for j in range(1,i+1):         print(j, end="")     print()
output: def pattern_print(n):
      for i in range(1, n + 1):
          for j in range(1, i + 1):
              print(j, end="")
          print()