MostOccuring.py

name = raw_input("Enter file:")
if len(name) < 1 : name = "mbox-short.txt"
handle = open(name)
emails = list()
count = dict()

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


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


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