input: Write a function to compare and explain the difference between a `list` and a `tuple` in Python. The function should return a string that describes how the two data structures can be differentiated in terms of mutability and syntax.
  assert compare_list_tuple()== "The difference between a list and a tuple in Python is that a list is mutable, meaning its contents can be changed, while a tuple is immutable, meaning its contents cannot be changed. A list has square brackets around it, while a tuple has parentheses around it. Lists are used when the data needs to be changed, while tuples are used when the data is fixed and cannot be changed."
output: def compare_list_tuple():
      return "The difference between a list and a tuple in Python is that a list is mutable, meaning its contents can be changed, while a tuple is immutable, meaning its contents cannot be changed. A list has square brackets around it, while a tuple has parentheses around it. Lists are used when the data needs to be changed, while tuples are used when the data is fixed and cannot be changed."