compressed file ended before the logical end-of-stream was detected

[Marc 'BlackJack' Rintsch]

In <1152084550.707264.48560 at m79g2000cwm.googlegroups.com>, Ritesh Raj
Sarraf wrote:

I have some remarks on exception handling.

> 1) compress_the_file() - This function takes files as an argument to it
> and put all of them into a zip archive
> 
> def compress_the_file(zip_file_name, files_to_compress, sSourceDir):
>     '''Condenses all the files into one single file for easy
> transfer'''
> 
>     try:
>         import zipfile
>     except ImportError:
>         sys.stderr.write("Aieeee! module not found.\n")

`zipfile` is part of the standard library.  So it should be there.  If it
isn't then you write the message and the program will run into a name
error exception because `zipfile` isn't imported then but you use it later
on.

>     try:
>         os.chdir(sSourceDir)
>     except:
>         #TODO: Handle this exception
>         pass

Don't do that!  This catches every exception and ignores it.  Write just a
comment instead that says something like `TODO: add proper exception
handling`.

>     try:
>         filename = zipfile.ZipFile(zip_file_name, "a")
>     except IOError:
>         #INFO By design zipfile throws an IOError exception when you
> open
>         # in "append" mode and the file is not present.
>         filename = zipfile.ZipFile(zip_file_name, "w")
>     except:
>         #TODO Handle the exception
>         sys.stderr.write("\nAieee! Some error exception in creating zip
> file %s\n" % (zip_file_name))
>         sys.exit(1)
> 
>     filename.write(files_to_compress, files_to_compress,
> zipfile.ZIP_DEFLATED)
>     filename.close()

Poor choice of names IMHO.  I expect `filename` to be a file name, i.e. a
string and `files_to_compress` is plural so one may expect a list or
another iterable.

This `import` wrapped into `try`/`except ImportError` idiom sprinkled all
over the source is a bit odd.  Just do your imports and wrap the main
programs function into `try`/`except` if you want to catch the
`ImportError`\s.  If you stop the program anyway this leads to much less
cluttered source code.

And it maybe would make sense to print the actual catched `IOError`\s too
because it may be a valueable information for the user *why* it failed. 
For example because he has no rights or the file system is full.

Ciao,
	Marc 'BlackJack' Rintsch