Produits Entr'ouvert » Calebasse

import os

def get_last_file(path, prefix=None, suffix=None):

    '''

    A filename is of format year-mont-day-hour-min-sec.xml or

    prefix_year-mont-day-hour-min-secsuffix

    If suffix is None, only file *_year-mont-day-hour-min-sec are treated.

    If prefix is None, all files *_year-mont-day-hour-min-secsuffix are

    treated.

    '''

    if not path or not os.path.isdir(path):

        return None

    cv_files = [(f, f) for f in os.listdir(path) \

            if os.path.isfile(os.path.join(path, f)) ]

    if prefix:

        cv_files = [(f1, f2[len(prefix) + 1:])

                for f1, f2 in cv_files if f2.startswith(prefix)]

    else:

        cv_files = [(f1, f2.rsplit('_', 1)[-1])

                for f1, f2 in cv_files]

    if suffix:

        cv_files = [(f1, f2[:-len(suffix)])

                for f1, f2 in cv_files if f2.endswith(suffix)]

    fmt = '%Y-%d-%m-%H-%M-%S'

    cv_files_and_dates = list()

    for f1, f2 in cv_files:

        try:

            d = datetime.strptime(f2, fmt)

        except:

            pass

        else:

            cv_files_and_dates.append((f1, d))

    if len(cv_files_and_dates):

        cv_files_and_dates = sorted(cv_files_and_dates,

                key=lambda x:x[1], reverse=True)

        return os.path.join(path, cv_files_and_dates[0][0])

    else:

        return None