a function that defines a final list using loops and tuples-CodePudding

i want to define a function that returns all the possible pairing of two giving tuples (including backwards). im new to python and having difficlty writing the correct function.

its supposed to look like this:

>>> first_tuple = (1, 2)
>>> second_tuple = (4, 5)
>>> mult_tuple(first_tuple, second_tuple)
((1, 4), (4, 1), (1, 5), (5, 1), (2, 4), (4, 2), (2, 5), (5, 2))

this is what i wrote and it doesnt work in any scenerio:

def mult_tuple(tuple1, tuple2):
 sofit = []
 for x in tuple1:
  for y in tuple2:
   sofit.append(x, y)
   sofit.append(y, x)
 return sofit

I WOULD APPRICIATE YOUR HELP

forgive my english

THANK YOU!

CodePudding user response：

You could use itertools.product and zip:

from itertools import product

def mult_tuple(a: tuple[int, ...], b: tuple[int, ...]) -> tuple[tuple[int, ...], ...]:
    return tuple(t for p in zip(product(a, b), product(b, a)) for t in p)
    # If you want to remove duplicates use below:
    # return tuple(set((t for p in zip(product(a, b), product(b, a)) for t in p)))    

first_tuple = (1, 2)
second_tuple = (4, 5)
print(mult_tuple(first_tuple, second_tuple))

Output:

((1, 4), (4, 1), (1, 5), (4, 2), (2, 4), (5, 1), (2, 5), (5, 2))

CodePudding user response：

You're almost there, note that append takes one argument so you need to pass the pair as a tuple:

first_tuple = (1, 2)
second_tuple = (4, 5)


def mult_tuple(tuple1, tuple2):
    sofit = []
    for x in tuple1:
        for y in tuple2:
            sofit.append((x, y))
            sofit.append((y, x))
    return sofit

answer = mult_tuple(first_tuple, second_tuple)
print(answer)

output:

[(1, 4), (4, 1), (1, 5), (5, 1), (2, 4), (4, 2), (2, 5), (5, 2)]

CodePudding user response：

Since @ItayB has already answered your question about the algorithm, I am going to give you another way to do it.

The itertools module consists of many useful functions, one of which is combinations()

The code:

tuple(
    set(
        list(combinations(first_tuple   second_tuple, 2))
          list(combinations(reversed(first_tuple   second_tuple), 2))
    )
)

We run it reversed as well because your requirement specifically asks for both (1,5) and (5,1). Another approach could've been to use list comprehension to reverse the tuples, an exercise I am leaving to OP.

Admittedly, this is a poor use of the function, especially because of the syntax. I am sure somebody could point out some improvements. But the point was to introduce the very helpful itertools.