Counting alphabets in a file

alphabet_counter.py

d = dict()
with open('lipsum.txt') as f:
    for line in f:
        for i in line:
            if i.isalpha():
                d[i.upper()] = d.get(i.upper(), 0) + 1
for key, val in sorted(d.items()):
    print("%s : %d" % (key, val))