Python time processing -- datetime examples

In many chapters of Python Cookbook PDF, it is focused on how to use a lib or how to combine multiple functions to implement a complex functionality. Here we skip all these details and go straight into how to process time in python. 

At the meantime, we simple introduce how to use datetime. 
Examples：
how the get the previous Friday and output it. 
Solutions：

code:

import datetime, calendar 

lastFriday = datetime.date.today( ) 
oneday = datetime.timedelta(days=1) 
lastFriday -= oneday 
while lastFriday.weekday( ) != calendar.FRIDAY: 
lastFriday -= oneday 
print lastFriday.strftime('%A, %d-%b-%Y') 

output：
Friday, 09-May-2008