Creating a list of files in a directory

[Fredrik Lundh]

Jeff Klassen wrote:
> I am new to Python. As a non-programmer I am encouraged by the level of
> 'success' I feel I have had, relative to similar learning attempts in other
> languages.
>
> I would like to simply do the following:
> - read all of files of a particular form (e.g. *.cev) from a particular
> directory

files = glob.glob("*.cev")
for file in files:

> - manipulate them with a series of re.sub expressions

are you sure?

> - write each file to its own output file with a certain form (e.g. *.out).

note that there's plenty of filename-manipulating stuff
in the os.path module.

for example:

    # split filename in file and extension part
    file, ext = os.path.splitext(file)
    outfile = file + ".out"

> workingdir=dircache.listdir('/jobs/python/learning/')

you're sure using somewhat confusing names; are you sure
you didn't really mean:

    workingdir='/jobs/python/learning/'
    allfiles = dircache.listdir(workingdir)

> filespec = re.compile(r'.*?\.cev')
> filestoprocess = []
>
> for allfiles in workingdir:
>     matchedfile=filespec.match(allfiles)

    for file in allfiles:
        matchedfile = filespec.match(file)

>     filestoprocess.append(matchedfile.group())
>
> print filestoprocess
> ----------------------------
>
> When I run this script I am returned:
> AttributeError: 'None' object has no attribute 'group'

the match method returns a match object (with a group method)
if it matches.  but if it doesn't, you get None.

this should work (but you probably want glob.glob anyway):

    matchedfile=filespec.match(allfiles)
    if matchedfile:
        filestoprocess.append(matchedfile.group())

hope this helps!

</F>