#!/usr/bin/env python
# -*- coding: utf-8 -*-
###############################################################################
# Copyright 2013 Kitware Inc.
#
# Licensed under the Apache License, Version 2.0 ( the "License" );
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
###############################################################################
"""This module contains utility methods for parsing girder path strings."""
import re
[docs]def encode(token):
"""Escape special characters in a token for path representation.
:param str token: The token to encode
:return: The encoded string
:rtype: str
"""
return token.replace('\\', '\\\\').replace('/', '\\/')
[docs]def decode(token):
"""Unescape special characters in a token from a path representation.
:param str token: The token to decode
:return: The decoded string
:rtype: str
"""
return token.replace('\/', '/').replace('\\\\', '\\')
[docs]def split(path):
"""Split an encoded path string into decoded tokens.
:param str path: An encoded path string
:return: A list of decoded tokens
:rtype: list
"""
# It would be better to split by the regex `(?<!\\)(?>\\\\)*/`,
# but python does't support atomic grouping. :(
chunks = path.split('/')
processed = [chunks[0]]
# matches an odd number of backslashes at the end of the string
escape = re.compile(r'(?<!\\)(?:\\\\)*\\$')
# Loop through the chunks and check if any of the forward slashes was
# escaped.
for chunk in chunks[1:]:
if escape.search(processed[-1]):
# join the chunks
processed[-1] = processed[-1] + '/' + chunk
else:
# append a new token
processed.append(chunk)
# now decode all of the tokens and return
return [decode(token) for token in processed]
[docs]def join(tokens):
"""Join a list of tokens into an encoded path string.
:param list tokens: A list of tokens
:return: The encoded path string
:rtype: str
"""
return '/'.join([encode(token) for token in tokens])