CODEWITHSUNDEEP
pythontuples
zachi
zachi

Reputation: 537

create a tuple from pairs

I would like to create a tuple which present all the possible pairs from two tuples

this is example for what I would like to receive :

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

output :

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

This is what I did which succeed however look a bit cumbersome :

def mult_tuple(tuple1, tuple2):
    ls=[]
    for t1 in tuple1:

        for t2 in tuple2:
            c=(t1,t2)
            d=(t2,t1)
            ls.append(c)
            ls.append(d)

    return tuple(ls)


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

The code I wrote works , however I am looking for a nicer code
thank you in advance

Upvotes: 24

Views: 6495

Answers (9)

Djaouad
Djaouad

Reputation: 22776

You can use itertools's product and permutations:

from itertools import product, permutations

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

result = ()

for tup in product(first_tuple, second_tuple):
    result += (*permutations(tup),)

print(result)

Output:

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

product produces the tuples (two elements) produced equally by the nested for loop structure (your t1 and t2 variables), and permutations produces the two permutations produced equally by your c and d variables.

Upvotes: 34

Billy Bonaros
Billy Bonaros

Reputation: 1721

My way in one line:

[item for sublist in [[(i,j),(j,i)] for i in first_tuple for j in second_tuple] for item in sublist]

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

Upvotes: 0

HEMANTA
HEMANTA

Reputation: 71

def mul_tup(tup1, tup2):
        l=[]

        for x in tup1:
            for y in tup2:
                a=(x,y)
                b=(y,x)
                l.append(a)
                l.append(b)

        return tuple(l)

first_tup= tuple([eval(x) for x in input("enter the values: ").split(',')])
second_tup= tuple([eval(x) for x in input("enter the values: ").split(',')])
q = mult_tup(first_tup, second_tup)
print(q)

Upvotes: -1

Alexander
Alexander

Reputation: 109546

A one-liner using a list comprehension that doesn't require an import.

t1 = (1, 2)
t2 = (4, 5)

>>> sorted([t for i in t1 for j in t2 for t in ((i, j), (j, i))])
# [(1, 4), (1, 5), (2, 4), (2, 5), (4, 1), (4, 2), (5, 1), (5, 2)]

Of course, for "all possible pairs from two tuples means" that you would have at most eight tuple pairs in the result. You could explicitly reference them, which should be the fastest solution if this is time critical code (and if sorting is not required, it will be faster still).

>>> sorted(((t1[0], t2[0]), (t1[0], t2[1]), (t1[1], t2[0]), (t1[1], t2[1]), 
            (t2[0], t1[0]), (t2[0], t1[1]), (t2[1], t1[0]), (t2[1], t1[1])))
# [(1, 4), (1, 5), (2, 4), (2, 5), (4, 1), (4, 2), (5, 1), (5, 2)]

Optional: Use set to ensure only unique pairs are returned.

t1 = (1, 2)
t2 = (1, 2)

>>> sorted([t for i in t1 for j in t2 for t in ((i, j), (j, i))])
# [(1, 1), (1, 1), (1, 2), (1, 2), (2, 1), (2, 1), (2, 2), (2, 2)]

>>> sorted(set([t for i in t1 for j in t2 for t in ((i, j), (j, i))]))
# [(1, 1), (1, 2), (2, 1), (2, 2)]

Upvotes: 1

hilberts_drinking_problem
hilberts_drinking_problem

Reputation: 11602

Here is an ugly one-liner.

first_tuple = (1, 2)
second_tuple = (4, 5)
tups = [first_tuple, second_tuple]
res = [(i, j) for x in tups for y in tups for i in x for j in y if x is not y]
# [(1, 4), (1, 5), (2, 4), (2, 5), (4, 1), (4, 2), (5, 1), (5, 2)]

Unless you are using this for sport, you should probably go with a more readable solution, e.g. one by MrGeek below.

Upvotes: 12

Andrej Kesely
Andrej Kesely

Reputation: 195438

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

out = []
for val in first_tuple:
    for val2 in second_tuple:
        out.append((val, val2))
        out.append((val2, val))

print(tuple(out))

Prints:

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

Upvotes: 3

ansev
ansev

Reputation: 30920

Also You can do:

from itertools import permutations 
t1=(1,2)
t2=(3,4)
my_tuple=tuple([key for key in filter(lambda x: x!=t1 and (x!=t2),list(permutations(t1+t2,2)))])

Upvotes: 2

chepner
chepner

Reputation: 531125

itertools.product gives you what you want. However, since the Cartesian product of two tuples is not commutative (product(x,y) != product(y,x)), you need to compute both and concatenate the results.

>>> from itertools import chain, product
>>> x = (1,4)
>>> y = (2, 5)
>>> list(chain(product(x,y), product(y,x)))
[(1, 2), (1, 5), (4, 2), (4, 5), (2, 1), (2, 4), (5, 1), (5, 4)]

(You can use chain here instead of permutations because there are only two permutations of a 2-tuple, which are easy enough to specify explicitly.)

Upvotes: 8

donkopotamus
donkopotamus

Reputation: 23176

If you’d like to avoid the use of the standard library (itertools) then simply combine two list comprehensions:

result = [(x, y) for x in first_tuple for y in second_tuple]
result.extend( (x, y) for x in second_tuple for y in first_tuple )

then convert to a tuple if it’s important to you.

Upvotes: 5

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