Question

I’m trying to learn the python scripting . Being some body who started coding in c/c++ or java i’m finding it extremely hard to find ways to write loops in python , especially for loops with conditions

I’ve a list A of string,
i need to do a specific op on these strings a pair at a time ,say xor of the strings
Also xor(a,b)=xor(b,a), hence i need to remove the redundant pair while looping

In traditional lang i would do something like

for(i=0;i<len;i++){
    for(j=i+1;j<len;j++){
        res[count]=xor(a[i],a[j])
        count++;
    }
}

So how do I implement the same with Python, I could think of iterators but is there a more efficient way , something very obvious eluding my eyes???

Answer 1

Python comes with batteries included, that is, most of the stuff like this is already written for you. If you want combinations of strings, there is a dedicated function for that:

import itertools

result = []
for pair in itertools.combinations(a, 2):
    result.append(xor(pair[0], pair[1]))

or simply:

 result = [xor(*p) for p in itertools.combinations(a, 2)]