file = open('pověst.txt','r')
kniha = file.read()

def tokenize():
    if kniha is not None:
        slova = kniha.lower().split()
        return slova
    else:
        return None

def count_slova(tokens):
    počet = 0
    words = {}
    for prvek in tokens:

        word = prvek.replace(",","")
        word = word.replace(".","")
        if word in words.keys():
            words[word]+=1
        else:
            words[word]=1
    return words



slova=tokenize()
frequency=count_slova(slova)
for k, v in frequency.items():
    print(k,":", v)