[Tutor] sys.exit() not working

fleet@teachout.org fleet@teachout.org
Sat, 4 Aug 2001 16:30:02 -0400 (EDT)

In the following code sys.exit() fails on the first test (denoted
<---FAILS); but works fine on the second test (denoted <---WORKS).

The only difference I see is that in the second test I provide an error
condition and in the first test I don't.  Which brings me to another
question:  The error returned if there are no jpg/JPG files in the
directory appears to be a shell error message (RH Linux 7.0) and not a
Python error (because of popen, I presume).  If I *need* an error
condition after except, what do I put there (first test)?

What occurs now, if this is run with no jpg/JPG files in the directory, is
the error message for test one gets printed, the test one 'sys.exit()'
gets ignored and the following test gets run.  Entering a "return" there
causes that test to fail, and the test 2 error message gets printed and
the file exits to my shell (from whence it was launched).

					- fleet -

#! /usr/bin/python

Creates body of Sylvia's E-bay index.  At this point, file sizing must be completed, captions
file must be cleaned up and everything ready to go.

import os
import sys
import string

# Get list of .jpg (or .JPG) files
   files=string.split(os.popen("ls -1D *.[jJ][pP][gG]").read(),"\012")
   print "ls: *.[jJ][pP][gG]: No such file or directory"
   sys.exit()          #<--- FAILS

# Get captions
   captions=string.split(open(raw_input("Enter Captions filename: "),"r").read(),"\012")
except IOError:
   print "No such file"
   sys.exit()          #<--- WORKS

# Compare lengths of files and captions
if len(files) == len(captions):
   print "Nr. of files (%s) doesn't match Nr. of captions (%s)" % (len(files), len(captions))

# Create temp.html for insertion into index.html

# The last line in "files" and "captions" is empty; hence len(files)-1
# write filenames and captions to temp.html
for i in range(0,len(files)-1):
   temp.write('<li><a href=\"%s\">(%s) - %s</a></li>\n' % (files[i], files[i], captions[i]))

# close temp.html

# get index.html from the mirror directories
os.popen("cp /home/raq2/brickhouse/ebay/index.html /home/dev/brickhouse/ebay")

# exit