[Tutor] Help with ARGV parsing

[Hans Nowak]

On 31 May 99, Jerry Alexandratos wrote:

> I'm new to Python.  But I really like what I see so far.  I'm looking to
> write and rewrite some scripts.  I'm having some trouble trying to
> figure out how to parse command-line arguments under Python.
> 
> Can anyone provide me with some pointers?

The most straightforward way is to look at sys.argv, a list which 
contains the command line arguments.

Try this very tiny program:

---begin--->8------

import sys
print sys.argv[1:]

---end----->8------

Now call this little script on the command line with various 
arguments, and see what happens.

showargs.py 1 2 3

just yields ['1', '2', '3'], but

showargs.py 1 "hello world" 2 

yields ['1', 'hello world', '2']

Some more experimenting won't hurt. :o) Note that each element of 
sys.argv is a string. Also note that I used a slice, sys.argv[1:]. 
The 0th argument of the list is the name of the calling program.

If you need more sophisticated parsing, you can take a look at the 
getopt module. You can specify switches and such. I think there are 
also a few third party modules around which also deal with parsing of 
the command line.

Veel liefs,

--Hans Nowak (ivnowa@hvision.nl)
Homepage: http://fly.to/zephyrfalcon