#!/usr/bin/python3
# ===================================================================
# search multiple directories for regular files that match
# one of multiple file name patterns (regular expression)
# ===================================================================

import re
import os

pats = [r'\.html$', r'\.py$', r'\.txt$' ]  # list of
                                           #   file name patterns
dirs = ['.', './z']                        # list of directories


# -------------------------------------------------------------------
# create a list of all file names that match a specified pattern
# in a directory
#
# dirs   list of directories to search
# pats   list of regexp to match file names
# lst    returned list of files names (path + name)
# -------------------------------------------------------------------

def list_of_files(dirs,pats):

    lst = []

    # ---- for each directory

    for d in dirs:

        # ---- names of files in directory

        fils = os.listdir(d)

        # ---- directory (path) must end in '/'

        if not re.search('\/$',d):
            d = d + '/'

        for f in fils:

            # ---- file path + name

            ff = d + f

            # ---- regular file?

            if not os.path.isfile(ff):
                continue

            # ---- file name matches a pattern?

            for p in pats:
                if re.search(p,f):
                    # ---- save absolute path + name
                    lst.append(os.path.abspath(ff)))
                    break
    return lst

# -------------------------------------------------------------------
# ---- main
# -------------------------------------------------------------------

if __name__ == '__main__':

    lst = list_of_files(dirs,pats)  # get list of files

    print(sorted(lst))              # print sorted file list