I’m trying to find all the letters in a list that differ from each other by word. I then output them into an array. The trouble is it takes my current code 17 seconds for 18, 000 words and I trying to cut down the time it takes.

Is there anyway I can speed this up?

#compares words and returns true if they are neighbours                     
def isneighbour(word1, word2):
    diff = 0
    for i in range(len(word1)):
        if word1[i] != word2[i]:
            diff += 1
            if diff > 1:
                return False
    return diff == 1
        
        
                        
def find_neighbours(lst):
    #take a word from lst
    #compare to rest of words from lst
    hood = []
    #convert dictionary to list
    #search for all words of same length
    keylst = list(lst.keys())
    length = len(keylst) -1
    for i in range(0, length -1):
        temp = []
        temp.append(keylst[i])
        for j in range(i + 1, length):
            if len(keylst[i]) == len(keylst[j]):
                #test to see if two words of the same length are neighbours             
                if isneighbour(keylst[i], keylst[j]):
                    temp.append(keylst[j])
        if len(temp)>1:
            quicksort(temp)
            hood.append(temp)   
    return hood

I’ve had a google around and can’t see how I can improve on this. I am student, so all suggestions will be useful.