# HG changeset patch
# User amit@shrike.aero.iitb.ac.in
# Date 1272014831 -19800
# Node ID 3451e2b9002e35eb25084acd682c9e3ef0f52577
# Parent  7722d269ff8255112cae2604712a266a8f804c34
Started with functions second session day2

diff -r 7722d269ff82 -r 3451e2b9002e functions_.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/functions_.txt	Fri Apr 23 14:57:11 2010 +0530
@@ -0,0 +1,13 @@
+While we have talked about how you can do simple tasks in Python we haven't started to talk about how you can organize your code . One of the first techniques we use to break a task into  relatively independent subtask . These can share data with  other parts of the program . These code blocks clubbed together are called functions or subroutines . 
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+def keyword in Python is used to define a function. 
+Arguments are local to a function , i.e you can access the arguments only in a particular function in other places it shall raise a Name error . 
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+One of the great things about python is that a function can return multiple values . Essentialy it does it by  packing the multiple values in a tuple .
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+Lets look at how to write functions by writing one out .
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+We have given the function the name signum . Essentially what it does is that based on whether the no is 0 , negative or positive , it returns 0 , -1 and +1 respectively . In this case it recieves value of the no in variable r .    
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+In the beginning of the function you can see a triple quoted string . This is called a docstring . You can write some documentation related to your function. In this you can have the function parameters and what it returns . A python function returns a value by using the keyword return .
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