Sorting directory contents

[Rob Wolfe]

Wolfgang Draxinger wrote:

> However this code works (tested) and behaves just like listdir,
> only that it sorts files chronologically, then alphabetically.
>
> def listdir_chrono(dirpath):
>         import os
>         files_dict = dict()
>         for fname in os.listdir(dirpath):
>                 mtime = os.stat(dirpath+os.sep+fname).st_mtime
>                 if not mtime in files_dict:
>                         files_dict[mtime] = list()
>                 files_dict[mtime].append(fname)
>
>         mtimes = files_dict.keys()
>         mtimes.sort()
>         filenames = list()
>         for mtime in mtimes:
>                 fnames = files_dict[mtime]
>                 fnames.sort()
>                 for fname in fnames:
>                         filenames.append(fname)
>         return filenames

Using the builtin functions `sorted`, `filter` and the `setdefault`
method of dictionary could a little shorten your code:

def listdir_chrono(dirpath):
    import os
    files_dict = {}
    for fname in filter(os.path.isfile, os.listdir(dirpath)):
        mtime = os.stat(os.path.join(dirpath, fname)).st_mtime
        files_dict.setdefault(mtime, []).append(fname)

    filenames = []
    for mtime in sorted(files_dict):
        for fname in sorted(files_dict[mtime]):
            filenames.append(fname)
    return filenames

--
HTH,
Rob