bazarr/libs/arghelper.py

117 lines
3.2 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2014-2016 The arghelper developers. All rights reserved.
# Project site: https://github.com/questrail/arghelper
# Use of this source code is governed by a MIT-style license that
# can be found in the LICENSE.txt file for the project.
"""Provide helper functions for argparse
"""
# Try to future proof code so that it's Python 3.x ready
from __future__ import print_function
from __future__ import unicode_literals
from __future__ import division
from __future__ import absolute_import
# Standard module imports
import argparse
import sys
import os
def extant_file(arg):
"""Facade for extant_item(arg, arg_type="file")
"""
return extant_item(arg, "file")
def extant_dir(arg):
"""Facade for extant_item(arg, arg_type="directory")
"""
return extant_item(arg, "directory")
def extant_item(arg, arg_type):
"""Determine if parser argument is an existing file or directory.
This technique comes from http://stackoverflow.com/a/11541450/95592
and from http://stackoverflow.com/a/11541495/95592
Args:
arg: parser argument containing filename to be checked
arg_type: string of either "file" or "directory"
Returns:
If the file exists, return the filename or directory.
Raises:
If the file does not exist, raise a parser error.
"""
if arg_type == "file":
if not os.path.isfile(arg):
raise argparse.ArgumentError(
None,
"The file {arg} does not exist.".format(arg=arg))
else:
# File exists so return the filename
return arg
elif arg_type == "directory":
if not os.path.isdir(arg):
raise argparse.ArgumentError(
None,
"The directory {arg} does not exist.".format(arg=arg))
else:
# Directory exists so return the directory name
return arg
def parse_config_input_output(args=sys.argv):
"""Parse the args using the config_file, input_dir, output_dir pattern
Args:
args: sys.argv
Returns:
The populated namespace object from parser.parse_args().
Raises:
TBD
"""
parser = argparse.ArgumentParser(
description='Process the input files using the given config')
parser.add_argument(
'config_file',
help='Configuration file.',
metavar='FILE', type=extant_file)
parser.add_argument(
'input_dir',
help='Directory containing the input files.',
metavar='DIR', type=extant_dir)
parser.add_argument(
'output_dir',
help='Directory where the output files should be saved.',
metavar='DIR', type=extant_dir)
return parser.parse_args(args[1:])
def parse_config(args=sys.argv):
"""Parse the args using the config_file pattern
Args:
args: sys.argv
Returns:
The populated namespace object from parser.parse_args().
Raises:
TBD
"""
parser = argparse.ArgumentParser(
description='Read in the config file')
parser.add_argument(
'config_file',
help='Configuration file.',
metavar='FILE', type=extant_file)
return parser.parse_args(args[1:])