class Compare(Expr): """A sequence of comparison operations. In Python, it is possible to chain together comparison operations: x1 <= x2 < x3 <= x4 This is logically equivalent to the more explicit binary form: (x1 <= x2) and (x2 < x3) and (x3 <= x4), except each middle expression is only evaluated once. === Attributes === left: the leftmost value being compared. (in the example above, this is `x1`) comparisons: a list of tuples, where each tuple stores an operation and expression (in the example above, this is [('<=', x2), ('<', x3), ('<=', x4)]) === Representation Invariants === - len(self.comparisons) >= 1 - the first element of every tuple in self.comparisons is '<=' or '<'. """ left: Expr comparisons: List[Tuple[str, Expr]] def __init__(self, left: Expr, comparisons: List[Tuple[str, Expr]]) -> None: """Initialize a new comparison expression.""" self.left = left self.comparisons = comparisons # TODO: implement this method! def evaluate(self) -> Any: """Return the *value* of this expression. The returned value should be the result of how this expression would be evaluated by the Python interpreter. NOTE: you don't need to worry about checking types of expressions; in Python, it's actually valid to compare integers and booleans (although generally we don't do this in CSC148). NOTE: You are NOT not allowed to use eval() at all in this function. It is dangerous. >>> expr = Compare(Num(1), [ ... ('<=', Num(2)), ... ('<', Num(4.5)), ... ('<=', Num(4.5))]) >>> expr.evaluate() True """ pass def __str__(self) -> str: """Return a string representation of this comparison expression. >>> expr = Compare(Num(1), [ ... ('<=', Num(2)), ... ('<', Num(4.5)), ... ('<=', Num(4.5))]) >>> str(expr) '(1 <= 2 < 4.5 <= 4.5)' """ s = str(self.left) for operator, subexpr in self.comparisons: s += f' {operator} {str(subexpr)}' return '(' + s + ')'

PLEASE IMPLEMENT THE FOLLOWING METHOD USING PYTHON 3.8 AND READ THE INSTRUCTIONS IN THE DOCSTRINGS CAREFULLY BECAUSE THERE ARE SOME RULES THAT YOU MUST FOLLOW.