[Tutor] Cannot understand what this means

[Alan Gauld]

On 15/07/13 09:53, #PATHANGI JANARDHANAN JATINSHRAVAN# wrote:

> websites. But now, there is a program from Google's Python Exercises
> whose main() part is already given to you.
>
>
> def main():
>    # This command-line parsing code is provided.
>    # Make a list of command line arguments, omitting the [0] element
>    # which is the script itself.
>    args = sys.argv[1:]
>
>    if not args:
>      print 'usage: [--summaryfile] file [file ...]'
>      sys.exit(1)
>
>    # Notice the summary flag and remove it from args if it is present.
>    summary = False
>    if args[0] == '--summaryfile':
>      summary = True
>      del args[0]

> My problem is that I cannot understand anything in this main() module.
> Nothing at all.

It sounds like you need a more basic tutorial then.

Do you really not know what

def main():

means?

Hint: its a function not a module...

And do you know what "command line arguments" are?
Or what sys.argv represents?

Do you understand sys.exit()?
I assume 'print' is self explanatory?

Does the 'if' test mean anything?

If you really don't understand any of those things
you need to find a more basic tutorial and work
through it. (You might try the first part of mine,
see below, as an example)

If you do understand those constructs, then you
understand quite a lot of main and need to ask
a more specific question.

-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/