ls files --> list packer

[kpp9c]

I would like to use the power of Python to build some list structures
for me.

Namely i have organized a bunch of folders that have soundfiles in them
and would like Python to slurp up all the .aif/.aiff (or .wav whatever)
files in a given set of directories. My friend hacked up this is perl:

$files = `ls /snd/Public/*.aiff`;

@snd_filelist = split('\n',$fil es);

$i = 0;
while ($file = @snd_filelist[$i]) {
print "file $i = @snd_filelist[$i]\n";
$i++;
}
The only catch with the above code (besides its hideousness hee hee) is
if you have a directory w/i the structure, but in general it works and
with this i can just put gobs of files into separate dirs pack them
into a list and then send them to my script that scrambles them and
plays them.

I would like something similar, that works with python that is more
elegant and maybe even more robust.

but i am failing miserably and my perl friends mock me.

cheers,
kp8

[Kent Johnson]

kpp9c wrote:

os.listdir works great ... just one problem, it packs the filenames
only into a list... i need the full path and seach as i might i se NO
documentation on python.org for os.listdir()
Docs for os.listdir() are here:
http://docs.python.org/lib/os-file-dir.html

When all else fails try the index:
http://docs.python.org/lib/genindex.html
how do i either grab the full path or append it later ...

Use os.path.join():

base = '/some/useful/path'
for f in os.listdir(base ):
full_path_to_fi le = os.path.join(ba se, f)

Kent

[kpp9c]

Thank you... i was looking in the wrong place cause all i found was
this relatively useless doc:

http://docs.python.org/lib/module-os.html

which says almost nothing.

[kpp9c]

nice! two little lines that do a boatload of work! hee hee

----
pth = '/Users/kpp9c/snd/01'
samples = [os.path.join(pt h, f) for f in os.listdir(pth) if
f.endswith('.ai f')]
----

thank you Kent! (and Jeremy and Magnus and Singletoned and I V ... and
john boy and mary ellen .. )

[Scott David Daniels]

kpp9c wrote:

Thank you... i was looking in the wrong place cause all i found was
this relatively useless doc:
http://docs.python.org/lib/module-os.html
which says almost nothing.

In one of its subsections, cleverly named "Files and Directories",
I see a nice description of listdir.

http://docs.python.org/lib/os-file-dir.html

You also might want to read about os.walk in the same page.
In the os.path module you can see more path name manipulations.
If you intend to know a language, you should read its manuals
fast; what you want is a vague impression where information
lives and what information is there. Maybe half a year later
do it again. After that every couple of years often suffices.
At the very least, go through the full tutorial, read docs on
the "obvious" modules for everyone and for your particular
area of endeavor, and then on a snacking basis get yourself
through the rest unless you decide that you never want to deal
with, for example, unix-specific services or internet protocols.

Don't expect to acquire _any_ language with "just in time" (JIT)
techniques. Perhaps JIT works for magic. When you acquire a
language with JIT, you miss the subtleties of the language.
You will be doomed to writing the same kinds of programs in every
language you touch ("writing Fortran in Algol" is what we used to
call it). I've worked on code that was Java-in-Python, and it was
frustratingly hard to understand.

--Scott David Daniels
sc***********@a cm.org

[Magnus Lycka]

kpp9c wrote:

that is nice.... but the little further wrinkle, which i have no idea
how to do, would be to have the contents of each directory packed into
a different list.... since you have no idea before hand how many lists
you will need (how many subdirs you will enounter) ... well that is
where the hairy part comes in...

What's the problem? If you'll get an unknown bundle of objects in a
program, you just put them in a container. A list or a dict will do
fine. Have a look at the Python tutorial.

You get a file list for each directory from os.walk. You either keep
a list called "directorie s" and for each turn in the loop, you do
"directories.ap pend((dir, sound_files))", or you have a dict called
"directorie s", and do "directorie s[dir] = sound_files" in the loop.

Something like this untested code:

def isSoundFile(x):
# home work

dirs = {}
root = raw_input('star t directory')
for dir, dummy, files in os.walk(root):
dirs[dir] = [x for x in files if isSoundFile(x)]

for dir in sorted(dirs):
print dir
for fn in dirs[dir]:
print "\t", fn
print