'''
Created on Nov 9, 2017

@author: Susan
'''
def emailsLargest(courses):
    d = {}
    for item in courses:
        [course,name,email] = item.split(":")
        if course not in d:
            d[course] = [email]
        else:
            d[course].append(email)
    print d



if __name__ == '__main__':
    alist = ["CompSci 100:Fred Jack Smith:fjs@duke.edu", 
   "History 117:Fred Jack Smith:fjs@duke.edu", 
   "CompSci 102:Arielle Marie Johnson:amj@duke.edu", 
   "CompSci 100:Arielle Marie Johnson:amj@duke.edu", 
   "CompSci 006:Bertha White:bw@duke.edu",
   "Econ 051:Bertha White:bw@duke.edu", 
   "English 112:Harry Potter:hp@duke.edu",
   "CompSci 100:Harry Potter:hp@duke.edu"]
    
    x = emailsLargest(alist)