[Tutor] Running Python from UNIX

[alan.gauld@bt.com]

> environment. I wrote a small function to compute fibonacci series. 

> If I write this as a script and execute the script, 
> it runs without errors but does not print the result. 

My guerss is that in the script file you have 
defined the function but not executed it.

######### foo.py ########

# define function foo
def foo():
   print 'foo'

# now execute it

foo()

######## End of foo.py ########


Without the foo() line when you run the script the 
function foo will be defined but not executed.

To allow you to import the script or execute it we 
usually add the following bit of magic syntax at 
the end of the file:

if __name__ == "__main__":
   foo()

then you can import foo and define but not execute 
the function or run it as a script in its own right 
in which case foo() will be executed too.

> code the same function as a regular program, 
> then it works as a script too. 

Thats because its now not a function so each 
line gets executed when the file runs.

HTH,

Alan g.
Author of the 'Learning to Program' web site
http://www.freenetpages.co.uk/hp/alan.gauld