Get frequency of letters in a given body of text

letterfrequency.py

#!/bin/python

text = \
'''Sing in me, Muse, and through me tell the story
of that man skilled in all ways of contending,
the wanderer, harried for years on end,
after he plundered the stronghold
on the proud height of Troy.

He saw the townlands
and learned the minds of many distant men,
and weathered many bitter nights and days
in his deep heart at sea, while he fought only
to save his life, to bring his shipmates home.'''

frequency = {'space':0,'punct':0,'a':0,'b':0,'c':0,'d':0,'e':0,'f':0,'g':0,'h':0,'i':0,'j':0,'k':0,'l':0,'m':0,'n':0,'o':0,'p':0,'q':0,'r':0,'s':0,'t':0,'u':0,'v':0,'w':0,'x':0,'y':0,'z':0}

def getFrequency(text):
    text = text.lower()
    for l in text:
        if l == ' ':
            l = 'space'
        if not l.isalpha():
            l = 'punct'
        frequency[l] += 1
    for letter in sorted(frequency):
        if letter is not 'space' and letter is not 'punct':
            print(letter, frequency[letter])

def main():
    getFrequency(text)

if __name__=='__main__':
    main()