input: Write a function to explain the difference between a list and a tuple in Python. If the input is "list" return the explanation that a list is mutable and has square brackets around it, and if the input is "tuple" return the explanation that a tuple is immutable and has parentheses around it. If the input is neither "list" nor "tuple", return "Invalid input".
  assert difference_between_list_tuple("list")=="A list is mutable, meaning its contents can be changed, and has square brackets around it."
  assert difference_between_list_tuple("tuple")=="A tuple is immutable, meaning its contents cannot be changed, and has parentheses around it."
  assert difference_between_list_tuple("dictionary")=="Invalid input"
  assert difference_between_list_tuple("set")=="Invalid input"
output: def difference_between_list_tuple(input_type):
      if input_type == "list":
          return "A list is mutable, meaning its contents can be changed, and has square brackets around it."
      elif input_type == "tuple":
          return "A tuple is immutable, meaning its contents cannot be changed, and has parentheses around it."
      else:
          return "Invalid input"