How to combine two lists to get all combinations (ie. list1=["a","b", "c"] list2=["1","2","3"] wantedoutcome=["a1","a2","a3","b1","b2"...."c3"]

Question

I want to create a deck of cards by combining a list containing card values:

[7,8,9,10,J,Q,K,A]

and a list containing colors:

[♣,♥,♠,♢]

to get all combinations once.

Is there some simple way to combine lists (or strings) in this way?

I tried several ways but none worked (maybe because special characters used directly (♣,♥,♠,♢) and not in the \N{xxxxx} way? )

expected outcome would be list/dictionary containing all possible combinations exactly once:

["7♣","7♥","7♠","7♢","8♣","8♥","8♠","8♢", ....."A♣","A♥","A♠","A♢"]

thanks alot for helping guys :)

A for loop to iterate over ranks, another for loop to iterate over suits, nested inside the first loop. Print the current combination of rank + suit. Presto! — John Gordon, Sep 08 '19 at 16:20
Is the difficulty with an algorithm to generate the combinations or the special characters for the card suits? This will shape the answer. — paisanco, Sep 08 '19 at 16:22
The main problem is to create combination. "secondary question would be if i can use directly those four special characters or if i need to use \N{something} for them" — Martin Kočka, Sep 08 '19 at 16:25

score 3 · Answer 1 · answered Sep 08 '19 at 16:34

You want a Cartesian product. The itertools.product function does this, but you can also use two for loops.

[rank+suit for rank in ['7','8','9','10','J','Q','K','A'] for suit in '♣♥♠♢']

or

from itertools import product

[rank+suit for rank, suit in product(['7','8','9','10','J','Q','K','A'], '♣♥♠♢')]

score 1 · Accepted Answer · answered Sep 08 '19 at 16:34

A simple nested list-comprehension will do the trick:

nums = ['7','8','9','10','J','Q','K','A']
colors = ['♣','♥','♠','♢']

res = [num+color for num in nums for color in colors]

This gives:

['7♣', '7♥', '7♠', '7♢', '8♣', '8♥', '8♠', ..., 'K♥', 'K♠', 'K♢', 'A♣', 'A♥', 'A♠', 'A♢']

*output truncated

score 0 · Answer 3 · answered Sep 08 '19 at 16:38

Use itertools.product:

>>> ranks = ["7", "8", "9", "10", "J", "Q", "K", "A"]
>>> suits = ["♣","♥","♠","♢"]
>>> [''.join(x) for x in product(ranks, suits)]
['7♣', '7♥', '7♠', '7♢', '8♣', '8♥', '8♠', '8♢', '9♣', '9♥', '9♠', '9♢', '10♣', '10♥', '10♠', '10♢', 'J♣', 'J♥', 'J♠', 'J♢', 'Q♣', 'Q♥', 'Q♠', 'Q♢', 'K♣', 'K♥', 'K♠', 'K♢', 'A♣', 'A♥', 'A♠', 'A♢']

How to combine two lists to get all combinations (ie. list1=["a","b", "c"] list2=["1","2","3"] wantedoutcome=["a1","a2","a3","b1","b2"...."c3"]

3 Answers3