'''
Exercise 8.1 Write a function called chop that takes a list and modifies it, removing the first
and last elements, and returns None.
Then write a function called middle that takes a list and returns a new list that contains all but the first and last elements.
'''
def chop():
    list1=[1,2,3,4,5,6,7,8]
    list1.pop(0)
    list1.pop(len(list1)-1)
    return None
def middle():
    list2=[1,2,3,4,5,6,7,8]
    list2.pop(0)
    list2.pop(len(list2)-1)
    return list2

'''
Exercise 8.3 Rewrite the guardian code in the above example without two if statements.
Instead use a compound logical expression using the and logical operator with a single
if statement.
'''
fhand = open('mbox-short.txt')
count = 0
for line in fhand:
    words = line.split()
    # print 'Debug:', words
    if len(words) == 0 or words[0] != 'From': continue
    print words[2]

'''
Exercise 8.4 Download a copy of the file from www.py4inf.com/code/romeo.txt
Write a program to open the file romeo.txt and read it line by line. For each line, split the line into a list of words using the split function.
'''
fhand = open('romeo.txt')
for line in fhand:
    words=line.split()
    print words

'''
Exercise 8.5 Write a program to read through the mail box data and when you find line that
starts with “From”, you will split the line into words using the split function. We are interested
in who sent the message which is the second word on the From line.
From stephen.marquard@uct.ac.za Sat Jan 5 09:14:16 2008
You will parse the From line and print out the second word for each From line and then you will
also count the number of From (not From:) lines and print out a count at the end.
'''
fhand=open('mail.txt')
count=0
for line in fhand:
    words=line.split()
    if words[0]=='From':
        count=count+1
        print words[1]
    elif words[0]!='From':
        continue
print 'there are ',count,'lines that start with From'

'''
Exercise 8.6 Rewrite the program that prompts the user for a list of numbers and prints out
the maximum and minimum of the numbers at the end when the user enters “done”. Write the
program to store the numbers the user enters in a list and use the max() and min() fuctions to
compute the maximum and minimum numbers after the loop completes.
'''
a=raw_input('Enter a number:')
list=[]
while(a!='done'):
    list.append(a)
    a=raw_input('Enter a number:')
print list
print max(list)
print min(list)