Python - Contador de palabras

from collections import Counter

def az(filename):

    with open(filename) as f:

        return

def word_count(filename):

    with open(filename) as f:

        return Counter(f.read().split())

counter = word_count('E:/as.txt')

for i in counter:

    print(i,':',counter[i])

from collections import Counter

from functools import reduce

def eliminar_nueva_linea(line):

    return line.rstrip()

def filtrar_solo_letras_espacio(line):

    solo_letras = filter(lambda c: c.isalpha() or c.isspace(), line)

    return "".join(solo_letras)

def convertir_a_minusculas(line):

    return line.lower()

def procesar_archivo(file_name, composicion, counter_handler):

    counter = Counter()

    try:

        with open(file_name) as f:

            while True:

                line = composicion(next(f))

                counter.update(line.split())

    except StopIteration:

        pass

    counter_handler(counter)

def imprimir_resultado(counter):

    for k, v in counter.items():

        print(f"{k}: {v}")

file_name = 'cancion.txt'

funciones = [filtra_solo_letras_espacio, eliminar_nueva_linea, convertir_a_minusculas]

def composicion(*funciones):

    return reduce(lambda f, g: lambda x: f(g(x)), funciones, lambda x: x)

procesar_archivo(file_name, composicion(*funciones), imprimir_resultado)