Print a list of two outputs with no duplicates or similar duos

Question

I've searched high and low for a solution for my script, but with no luck.

I am trying to print every possible duo from a given list. Except, not printing duplicates such as (a, a). And not printing a combination twice such as if (a, b) has been printed, then (b, a) will not be printed.

FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
    "Pistachio",
    "Raspberry",
    "Strawberry",
    "Vanilla",
]

for i in FLAVORS:
    for j in FLAVORS:
        if (i != j) :
            print(i, j, sep=", ")

I've managed to not print duplicates such as (a, a). However, I am stuck on how to print a combination only once so if (a, b) is printed, (b, a) wont be printed.

You're probably looking for [`iterools.combinations()`](https://docs.python.org/3/library/itertools.html#itertools.combinations) — ti7, Jul 28 '21 at 17:09
Does this answer your question? [How to get all possible combinations of a list’s elements?](https://stackoverflow.com/questions/464864/how-to-get-all-possible-combinations-of-a-list-s-elements) — ti7, Jul 28 '21 at 17:10

score 1 · Answer 1 · 2021-07-28T17:10:51.400

1

You can use itertools.combinations

import itertools
FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
    "Pistachio",
    "Raspberry",
    "Strawberry",
    "Vanilla",
]
x=list(itertools.combinations(FLAVORS,2))
print(x)

edited Jul 28 '21 at 17:10

answered Jul 28 '21 at 17:09

Thank you, this worked great. I was specifically looking for the for loop way, to practice for loops, but I will take not of this. Thanks again. – AndrewGLeong Jul 28 '21 at 20:12

score 0 · Answer 2 · answered Jul 28 '21 at 17:11

0

Something like that?

FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
]
n = len(FLAVORS)

for i in range(n):
    for j in range(i+1, n):
        print(FLAVORS[i], FLAVORS[j], sep=", ")

Banana, Chocolate
Banana, Lemon
Chocolate, Lemon

answered Jul 28 '21 at 17:11

Gaëtan

198
7

Thank you, like the code above, this is exactly what I wanted :) so thank you. – AndrewGLeong Jul 28 '21 at 20:13

score 0 · Accepted Answer · answered Jul 28 '21 at 17:14

0

Here is the solution

FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
    "Pistachio",
    "Raspberry",
    "Strawberry",
    "Vanilla",
]

for i in range(len(FLAVORS)):
    for j in range(i+1,len(FLAVORS)):
        print(FLAVORS[i],FLAVORS[j],sep=",")

answered Jul 28 '21 at 17:14

Lakshika Parihar

1,017
9
19

Thank you, this is exactly what I wanted. Can you explain the for loop code, please? How does that work in terms of knowing not to print duplicates and duos? – AndrewGLeong Jul 28 '21 at 20:11
1

Ah, I've got it not. I used http://pythontutor.com/visualize. I tried this earlier and it was printing out the number of the item rather than the item. I see you need to put FLAVOURS[i] to print it out :) thank you thank you thank you – AndrewGLeong Jul 28 '21 at 20:18

Print a list of two outputs with no duplicates or similar duos

3 Answers3