Exercise 9.4 Python For Everybody

9.4 Write a program to read through the mbox-short.txt and figure out who has sent the greatest number of mail messages. The program looks for ‘From ‘ lines and takes the second word of those lines as the person who sent the mail. The program creates a Python dictionary that maps the sender’s mail address to a count of the number of times they appear in the file. After the dictionary is produced, the program reads through the dictionary using a maximum loop to find the most prolific committer.

fname = input("Enter file name: ")
fname = open("mbox-short.txt")
counts = dict()
emails = list()

for line in fname:
    if not line.startswith('From ') : continue
    words = line.split()
    emails.append(words[1])

for email in emails:
        counts[email] = counts.get(email, 0) + 1


bigcount = None
bigemail = None

for email, count, in counts.items() :
    if bigcount is None or count > bigcount:
        bigemail = email
        bigcount = count


print(bigemail, bigcount)