calibre command line convert books script

from datetime import datetime
import glob
import re
import shutil
import subprocess
import time
import os
import sys


def generate_unique_string():
    now = datetime.now()
    dt_string = str(now.strftime("%Y-%m-%d_%H-%M-%S-%f"))
    return dt_string


def create_dir(dir_loc):
    if os.path.isdir(dir_loc):
        pass
    else:
        os.mkdir(dir_loc)


def list_for_files(folder_loc, filter_string='*'):
    files_filtered = []
    files = glob.glob(folder_loc + os.sep + filter_string)
    for file in files:
        if os.path.isfile(file):
            files_filtered.append(file)
    files_filtered.sort()
    return files_filtered


def merge_files(extension, merge_dir, merge_name):
    read_files = glob.glob(merge_dir + os.sep + '*.' + extension)
    with open(merge_dir + os.sep + merge_name + '.' + extension, "wb") as outfile:
        for f in read_files:
            if os.path.isfile(f):
                with open(f, "rb") as infile:
                    outfile.write(infile.read())


def list_desktop(prefix):
    desktop_dir = os.path.join(os.environ['USERPROFILE'], 'Desktop')
    list_dir = os.listdir(desktop_dir)
    f_names = [string for string in list_dir if re.search('^' + prefix + '.*exe$', string)]
    if len(f_names) > 0:
        return desktop_dir, f_names[0]
    else:
        print('error, calibre portable exe file not found')


def setup_carlibre():
    # unpack portable installer
    desktop_dir, file_name = list_desktop('calibre-portable')
    converter_loc = desktop_dir + '\calibre\Calibre Portable\Calibre\ebook-convert.exe'
    if os.path.isfile(converter_loc):
        print('ebook-convert.exe present and ready to go...')
    else:
        os.chdir(desktop_dir)
        os.system(file_name + ' calibre')
    # setup input & output directories:
    input_dir = desktop_dir + '\calibre\input'
    create_dir(input_dir)
    done_dir = desktop_dir + '\calibre\input\done'
    create_dir(done_dir)
    output_dir = desktop_dir + '\calibre\output'
    create_dir(output_dir)
    return converter_loc, input_dir, done_dir, output_dir


def convert_files(convert_ext):
    converter_loc, input_dir, done_dir, output_dir = setup_carlibre()
    unique_string = generate_unique_string()
    output_dir = output_dir + os.sep + unique_string
    move_dir = done_dir + os.sep + unique_string
    input_files = list_for_files(input_dir)
    if len(input_files) > 0:
        for index, tmp_in in enumerate(input_files):
            file_name, file_ext = os.path.splitext(os.path.basename(tmp_in))
            print('converting file: ' + str(index+1) + ' / ' + str(len(input_files)) + ',\t' + file_name)
            create_dir(output_dir)
            out_loc = output_dir + os.sep + file_name + '.' + convert_ext
            create_dir(move_dir)
            move_loc = move_dir + os.sep + file_name + file_ext
            cmd = '"' + converter_loc + '" "' + tmp_in + '" "' + out_loc + '"'
            # print(cmd)
            response = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE).stdout.read().decode(
                'utf-8').splitlines()
            # print(response)
            shutil.move(tmp_in, move_loc)
        print('merging files into one:' + '\n' + output_dir + os.sep + unique_string + '.' + convert_ext)
        merge_files(convert_ext, output_dir, unique_string)
        print('process done, exiting...')
        time.sleep(5)
    else:
        print('error, copy some files into the "input" directory" and run it again...')
        time.sleep(5)


def run_code():
    if len(sys.argv) == 1:
        print('error, type "txt" or similar extension as an argument, example:')
        print('"' + sys.argv[0] + '" txt')
        time.sleep(5)
    elif len(sys.argv) == 2:
        convert_files(sys.argv[1])
    else:
        print('error, more than 1 argument given')
        time.sleep(5)


if __name__ == '__main__':
    run_code()