Structured bindings in Python-CodePudding

C 17 introduced the new structured bindings syntax:

std::pair<int, int> p = {1, 2};
auto [a, b] = p;

Is there something similar in python3? I was thinking of using the "splat" operator to bind class variables to a list, which can be unpacked and assigned to multiple variables like such:

class pair:
    def __init__(self, first, second):
        self.first = first
        self.second = second
...

p = pair(1, 2)
a, b = *p

Is this possible? And if so, how would I go by implementing this to work for my own classes?

A tuple in Python works as a simple solution to this problem. However, built in types don't give much flexibility in implementing other class methods.

CodePudding user response：

Yes, you can use __iter__ method since iterators can be unpacked too:

class pair:
    def __init__(self, first, second):
        self.first = first
        self.second = second
    def __iter__(self):
        # Use tuple's iterator since it is the closest to our use case.
        return iter((self.first, self.second))

CodePudding user response：

You can use tuples and tuple unpacking (see the bottom of this section in the Python documentation):

p = (1, 2)
a, b = p
print(a, b) # Prints 1 2