Random Rendszámok

import random

rendabc = list(map(chr, range(ord('A'), ord('Z')+1)))
arrayofabc = list()
abc = ""
for j in range(100):

    for i in range(3):
        valami = random.randrange(0,25)
        abc = abc+rendabc[valami]

    valami = random.randrange(0,999)+1

    abc = abc+"-"+str(valami)
    if abc not in arrayofabc:
        arrayofabc.append(abc)
    abc=""
print (arrayofabc)