Letter Count Dictionary

My homework problem is to write a Python function called LetterCount() which takes a string as an argument and returns a dictionary of letter counts. However, my code includes white space and commas as a part of the dictionary which i don’t want. Can you please help me out. How do i remove the white space from my list? Here is my code?

import string
def LetterCount(str):
    str= str.lower().strip()
    str = str.strip(string.punctuation)
    list1=list(str)
    lcDict= {}
    for l in list1:
        if l in lcDict:
            lcDict[l] +=1
        else:
            lcDict[l]= 1
    print lcDict

LetterCount("Abracadabra, Monsignor")

Answer

You can also check if l is an alphabetic character (if l.isalpha())

Example:

   import string
    def LetterCount(str):
            str= str.lower().strip()
            str = str.strip(string.punctuation)
            list1=list(str)
            lcDict= {}
            for l in list1:
                    if l.isalpha():
                            if l in lcDict:
                                    lcDict[l] +=1
                            else:
                                    lcDict[l]= 1
            print lcDict

    LetterCount("Abracadabra, Monsignor")