input: def evaluate_expression(expr: str) -> float:
      """
      Evaluates a given numerical expression in string format and returns the result.
      >>> evaluate_expression("2 + 3 * 4")
      14.0
      >>> evaluate_expression("(5 - 2) / 3")
      1.0
      """
      return float(eval(expr))
output:     return float(eval(expr))