Union with tuples Python

Question

import itertools

list_with_tuples=[(1,), (2,), (3,)]
pairs = itertools.combinations(list_with_tuples, 2)
for pair in pairs:
   print(pair)

so the result of pairs is :

 ((1,),(2,)) ,

 ((1,),(3)) ,

 ((2,),(3,))

How I can union them? After union I want to do a dictionary like:

di={ (1,2): value1, (1,3): value2, (2,3): value3 }

How can I do this?

Answer 1

One way to "union" tuples in python is to simply add them:

>>> (1,) + (2,)
(1, 2)

So you can modify your example to add:

import itertools

list_with_tuples=[(1,), (2,), (3,)]
pairs = itertools.combinations(list_with_tuples, 2)
for left, right in pairs:
     print(left + right)

Outputs:

(1, 2)
(1, 3)
(2, 3)

---

If you need to add n tuples, rather than just 2 of them, you can use sum and specify an initial value of the empty tuple () as the second argument.

Alternatively, as Kevin mentioned in the comments, you can build a new tuple by consuming the output of an itertools.chain, which will likely be more efficient if n is large.