Talking Movies - Python

Let's take a simple example, which demonstrates how to define a function and call it from different places within your Python program:

#!/usr/bin/python
# define a function
def greatMovie():
print "Star Wars"
# main program begins here
print "Question: which is the greatest movie of all time?"
# call the function
greatMovie()
# ask another question
print "Question: which movie introduced the world to Luke Skywalker, Yoda
and Darth Vader?"
# call the function
greatMovie()

Now run it - you should see something like this:

Question: which is the greatest movie of all time?
Star Wars
Question: which movie introduced the world to Luke Skywalker, Yoda and
Darth Vader?
Star Wars

Let's take this line by line. The first thing I've done is define a new function with the "def" keyword; this keyword is followed by the name of the function (and optionally, one or more arguments). All the program code attached to the function is then indented within this block - this program code could contain loops, conditional statements, or calls to other functions. In the example above, my function has been named "greatMovie", and only contains a call to Python's print() function.

Here's the typical format for a function:

def function_name(optional function arguments):
'comment'
statement 1...
statement 2...
.
.
.
statement n...

The comment line above allows the developer to optionally include a description of the function; if I wanted to be really verbose, I could modify the function definition in the example above to read

# define a function
def greatMovie():
'this prints the name of my favourite movie'
print "Star Wars"

>>> More Python Articles          >>> More By Vikram Vaswani, (c) Melonfire

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