Randomizing in all possible combinations in Python

Question

Here is my code:

if condition == '1':
    a = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist1/*")
    c = glob.glob("DDtest/targetimagelist2/*")
    d = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist4/*")
elif condition == '2':
    a = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist1/*")
    c = glob.glob("DDtest/targetimagelist2/*")
    e = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist4/*")
elif condition == '3':
    a = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist1/*")
    e = glob.glob("DDtest/targetimagelist2/*")
    d = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist4/*")
elif condition == '4':
    a = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist1/*")
    e = glob.glob("DDtest/targetimagelist2/*")
    c = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist4/*")
elif condition == '5':
    a = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist1/*")
    d = glob.glob("DDtest/targetimagelist2/*")
    c = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist4/*")
elif condition == '6':
    a = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist1/*")
    d = glob.glob("DDtest/targetimagelist2/*")
    e = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist4/*")
elif condition == '7':
    d = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist2/*")
    a = glob.glob("DDtest/targetimagelist2/*")
    c = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist4/*")
elif condition == '8':
    d = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist2/*")
    a = glob.glob("DDtest/targetimagelist2/*")
    e = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist4/*")
elif condition == '9':
    d = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist2/*")
    a = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist4/*")
elif condition == '10':
    d = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist4/*")
    e = glob.glob("DDtest/targetimagelist2/*")
    c = glob.glob("DDtest/distractorimagelist3/*")
    a = glob.glob("DDtest/targetimagelist4/*")
elif condition == '11':
    d = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist4/*")
    c = glob.glob("DDtest/targetimagelist2/*")
    e = glob.glob("DDtest/distractorimagelist3/*")
    a = glob.glob("DDtest/targetimagelist4/*")
elif condition == '12':
    d = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist2/*")
    a = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist4/*")
elif condition == '13':
    c = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist2/*")
    a = glob.glob("DDtest/targetimagelist2/*")
    d = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist4/*")
elif condition == '14':
    c = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist2/*")
    a = glob.glob("DDtest/targetimagelist2/*")
    e = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist4/*")
elif condition == '15':
    c = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist2/*")
    a = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist4/*")
elif condition == '16':
    c = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist4/*")
    e = glob.glob("DDtest/targetimagelist2/*")
    d = glob.glob("DDtest/distractorimagelist3/*")
    a = glob.glob("DDtest/targetimagelist4/*")
elif condition == '17':
    c = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist4/*")
    d = glob.glob("DDtest/targetimagelist2/*")
    e = glob.glob("DDtest/distractorimagelist3/*")
    a = glob.glob("DDtest/targetimagelist4/*")
elif condition == '18':
    c = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist2/*")
    a = glob.glob("DDtest/distractorimagelist3/*")
    e = glob.glob("DDtest/targetimagelist4/*")
elif condition == '19':
    e = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist2/*")
    a = glob.glob("DDtest/targetimagelist2/*")
    c = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist4/*")
elif condition == '20':
    e = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist2/*")
    a = glob.glob("DDtest/targetimagelist2/*")
    d = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist4/*")
elif condition == '21':
    e = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist2/*")
    a = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist4/*")
elif condition == '22':
    e = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist4/*")
    c = glob.glob("DDtest/targetimagelist2/*")
    d = glob.glob("DDtest/distractorimagelist3/*")
    a = glob.glob("DDtest/targetimagelist4/*")
elif condition == '23':
    e = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist4/*")
    d = glob.glob("DDtest/targetimagelist2/*")
    c = glob.glob("DDtest/distractorimagelist3/*")
    a = glob.glob("DDtest/targetimagelist4/*")
elif condition == '24':
    e = glob.glob("DDtest/targetimagelist1/*")
    b = glob.glob("DDtest/distractorimagelist3/*")
    d = glob.glob("DDtest/targetimagelist2/*")
    a = glob.glob("DDtest/distractorimagelist3/*")
    c = glob.glob("DDtest/targetimagelist4/*")

Basically what this does it is draws from a different list based on all combinations of a,c,d,e and makes a and b correspond. This code works fine, but it isn't very beautiful. I was wondering if anyone had any advice I do the same thing in fewer lines of code. More than anything I'm just trying to expand my knowledge of writing code, so if you know there is a more eloquent way of writing this let me know. :)

This might be a better fit for http://codereview.stackexchange.com — jonrsharpe, Mar 04 '15 at 19:55
Hmmm ... by my count, there should be 120 permutations of 5 items (taken 5 at a time)... You only seem to have 24. Am I missing something here? — mgilson, Mar 04 '15 at 20:00
I'd love to help on this, but the pattern is too unclear. You're swapping both the order of the variables and their data. Organize your data better and it will be easier to see the pattern. — Simon Forsberg, Mar 04 '15 at 20:08
In some of your conditions, the values for a and b are *identical* and not just *related* (9, 12 and 15 for example) - why? — Simon Forsberg, Mar 04 '15 at 20:12
You have tagged psychopy, yet the code does not contain any use of the psychopy module. Consider removing that tag. — Jonas Lindeløv, Mar 04 '15 at 21:00

score 2 · Answer 1 · answered Mar 04 '15 at 20:23

Not sure what you meant by "make a and b correspond", but maybe this would work:

from itertools import permutations
from random import choice

globs = [glob.glob("DDtest/targetimagelist1/*"),
         glob.glob("DDtest/distractorimagelist1/*"),
         glob.glob("DDtest/targetimagelist2/*"),
         glob.glob("DDtest/distractorimagelist3/*"),
         glob.glob("DDtest/targetimagelist4/*")]

glob_permutations = list(permutations(globs))

a, b, c, d, e = choice(glob_permutations)

score 1 · Answer 2 · answered Mar 04 '15 at 20:24

The built-in itertools library has a function for permutations without repetitions:

#!/usr/bin/env python2
import itertools
import glob

p = [
    glob.glob("DDtest/targetimagelist1/*"),
    glob.glob("DDtest/distractorimagelist4/*"),
    glob.glob("DDtest/targetimagelist2/*"),
    glob.glob("DDtest/distractorimagelist3/*"),
    glob.glob("DDtest/targetimagelist4/*"),
]

perm = itertools.permutations(p)

print(len(perm))

=> 120 permutations

score 0 · Answer 3 · answered Mar 04 '15 at 19:58

0

Maybe like that?

setup = {'1': ('1','1','2','3','4'),
         '2': ('1','1','2','3','4'),
        #...
        }
a = glob.glob("DDtest/targetimagelist" + setup[condition][0] + "/*")
b = glob.glob("DDtest/distractorimagelist" + setup[condition][1] + "/*")
c = glob.glob("DDtest/targetimagelist" + setup[condition][2] + "/*")
d = glob.glob("DDtest/distractorimagelist" + setup[condition][3] + "/*")
e = glob.glob("DDtest/targetimagelist" + setup[condition][4] + "/*")

answered Mar 04 '15 at 19:58

L3viathan

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Seems like you're just moving the problem from one spot to another. – Simon Forsberg Mar 04 '15 at 20:00
Does it? It makes for much shorter code, and I don't see how you could avoid listing it alltogether. Either that or I'm not seeing the connection between the condition and the combination. – L3viathan Mar 04 '15 at 20:03
1

Yeah, I think there's a connection we're not seeing because the question is not entirely clear. – Simon Forsberg Mar 04 '15 at 20:06

Randomizing in all possible combinations in Python

3 Answers3