input: Write a function to print a pattern consisting of increasing number of '*' followed by decreasing number of '*' based on the input, where the pattern increases up to a given number 'n' and then decreases back to 1.
  
  assert print_pattern(5)==None
  assert print_pattern(3)==None
output: def print_pattern(n):
      for i in range(1, n + 1):
          print('*' * i)
      for i in range(n - 1, 0, -1):
          print('*' * i)