import glob
import cv2 as cv
import numpy as np

def nn1(listoffnames, dist='L1'):
    # your function here, and return correct things
    # this is a placeholder to get my code to run
    return (listoffnames[0],listoffnames[1])

filelist = glob.glob('example-images/*.jpg')
# change to 'example-images\\*.jpg' on Windows
print(filelist)

listoflists = []

for i in range(len(filelist)):
    #print(filelist[0])
    listoflists.append(filelist.copy()) # make a copy of the list of names and append it 
    save = filelist[0] 
    filelist.remove(filelist[0])
    filelist.append(save)            # these 3 lines move the first file name to the end
                                     # which makes the list have a different first element 

print(listoflists)
# listoflists now contains n versions of the filelist with
# a different file name as the first element (to act as the key)

for i in range(len(listoflists)):
    #debug code to make sure the lists really had a different first element
    #print("list", i)
    #for j in range(len(listoflists[i])):
    #    print(listoflists[i][j])
    keyimgname, matchimgname = nn1(listoflists[i], 'L1')
    keyimg = cv.imread(keyimgname)
    matchimg = cv.imread(matchimgname)
    cv.imshow('key image', keyimg)
    cv.imshow('match image', matchimg)
    cv.waitKey(0)
    cv.destroyAllWindows()