CODEWITHSUNDEEP
pythonrecursiontuples
Pabloflopygame
Pabloflopygame

Reputation: 23

How can I use tuples in recursive functions?

I have to make a function where the input is a tuple consisting of 3 elements: elements 1 and 3 are numbers or other tuples with the same structure, and the second element is a string indicating an operation. An example would be (10, '-', (5, '*', 3)) and should return -5. The problem is that the function must be recursive and I can't find a way of working with tuples with recursive functions.

def evaluate(equation):
    if type(equation[0]) != tuple and type(equation[2]) != tuple:
        if equation[1] == "+":
            return equation[0] + equation[2]
        if equation[1] == "*":
            return equation[0] * equation[2]
        if equation[1] == "-":
            return equation[0] - equation[2]
        if equation[1] == "/":
            return equation[0] / equation[2]

I managed to create a foundation to operate, but I can't find an algorithm that finds all the empty tuples and keeps those values to operate latter.

Upvotes: 0

Views: 108

Answers (1)

Dan Nagle
Dan Nagle

Reputation: 5425

Evaluate the left and right sides of the tuple before performing the operation.

def evaluate(equation):
    left, operation, right = equation
    if type(left) == tuple:
        left = evaluate(left)
    if type(right) == tuple:
        right = evaluate(right)
    if operation == "+":
        return left + right
    elif operation == "*":
        return left * right
    elif operation == "-":
        return left - right
    elif operation == "/":
        return left / right

Upvotes: 2

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