#!/usr/bin/python

# P2PU - Python Programming - Chapter 5 - Datatypes
# Chapter 9 - Dictionaries
print 'Python for Informatics - Chapter 9: Dictionaries'

# Exercise 9.1
print '\n# Exercise 9.1\n'
fname =  'romeo.txt'
d = dict()
try:
    ffile = open(fname)
except:
    print 'File', fname, 'cannot be opened!'
    exit()
for line in ffile:
    words = line.split()
    for word in words:
        if word in d:
           d[word] += 1
        else:
           d[word] = 1
print d

# Exercise 9.2
print '\n# Exercise 9.2\n'
def histogram(s):
   d = dict()
   for c in s:
      d[c] = d.get(c, 0) + 1
   return d
print 'hippopotamus:', histogram('hippopotamus')

# Exercise 9.3
print '\n# Exercise 9.3\n'
fname =  'mbox-short.txt'
try:
    ffile = open(fname)
except:
    print 'File', fname, 'cannot be opened!'
    exit()
days = dict()
for line in ffile:
    words = line.split()
    if len(words) < 3 or words[0] != 'From': continue
    days[words[2]] = days.get(words[2], 0) + 1
print days

# Exercise 9.4
print '\n# Exercise 9.4\n'
fname =  raw_input('Enter file name: ')
try:
    ffile = open(fname)
except:
    print 'File', fname, 'cannot be opened!'
    exit()
mails = dict()
for line in ffile:
    words = line.split()
    if len(words) < 2 or words[0] != 'From': continue
    mails[words[1]] = mails.get(words[1], 0) + 1
mostName = None
mostCount = None
for mail in mails:
   if mostCount == None or mostCount < mails[mail]:
      mostName = mail
      mostCount = mails[mail]
print '%s : %d' % (mostName, mostCount)

# Exercise 9.5
print '\n# Exercise 9.5\n'
fname =  raw_input('Enter file name: ')
try:
    ffile = open(fname)
except:
    print 'File', fname, 'cannot be opened!'
    exit()
domains = dict()
for line in ffile:
    words = line.split()
    if len(words) < 2 or words[0] != 'From': continue
    domain = words[1].split('@')[1]
    domains[domain] = domains.get(domain, 0) + 1
print domains