Source code for

# Copyright 2011-2014 Biomedical Imaging Group Rotterdam, Departments of
# Medical Informatics and Radiology, Erasmus MC, Rotterdam, The Netherlands
# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

""" Module providing tools to parse and create valid urls and paths.

usage example:

When in fastr.config under the mounts section the data mount is set to /media/data, you will get the following.
.. code-block:: python

  >>> from import get_path_from_url
  >>> get_path_from_url('vfs://data/temp/blaat1.png')

import re
import os.path
import urllib.parse as up
import posixpath

from .. import resources
from fastr.exceptions import FastrUnknownURLSchemeError

[docs]def register_url_scheme(scheme): """ Register a custom scheme to behave http like. This is needed to parse all things properly. """ for method in [s for s in dir(up) if s.startswith('uses_')]: getattr(up, method).append(scheme)
[docs]def get_url_scheme(url): """ Get the schem of the url :param str url: url to extract scheme from :return: the url scheme :rtype: str """ parsed_url = up.urlparse(str(url)) return parsed_url.scheme
[docs]def get_path_from_url(url): """ Get the path to a file from a url. Currently supports the file:// and vfs:// scheme's Examples: .. code-block:: python >>> url.get_path_from_url('vfs://neurodata/user/project/file.ext') 'Y:\\neuro3\\user\\project\\file.ext' >>> 'file:///d:/data/project/file.ext' 'd:\\data\\project\\file.ext' .. warning:: file:// will not function cross platform and is mainly for testing """ # Translate properly depending on the scheme being used scheme = get_url_scheme(url) # Make the paths and vfs not go via ioplugins, but shortcut it if scheme == '': # This is not a URL, but a path, throw error raise FastrUnknownURLSchemeError('URL using no url scheme in {}, so it must be a path! '.format(url)) elif scheme == 'vfs': # Directly call vfs return resources.ioplugins['vfs'].url_to_path(url) else: # Dispatch to ioplugin via the ioplugin manager try: ioplugin = resources.ioplugins[scheme] except KeyError: raise FastrUnknownURLSchemeError('URL using an unknown scheme in {}' ' ({} not in {})'.format(url, scheme, list(resources.ioplugins.keys()))) return ioplugin.url_to_path(url)
[docs]def isurl(string): """ Check if string is a valid url :param str string: potential url :return: flag indicating if string is a valid url """ if not isinstance(string, str): return False parsed_url = up.urlparse(str(string)) return len(parsed_url.scheme) > 1
[docs]def basename(url): """ Get basename of url :param str url: the url :return: the basename of the path in the url """ parsed_url = up.urlparse(str(url)) return posixpath.basename(parsed_url.path)
[docs]def dirname(url): """ Get the dirname of the url :param str url: the url :return: the dirname of the path in the url """ parsed_url = up.urlparse(str(url)) return posixpath.dirname(parsed_url.path)
[docs]def dirurl(url): """ Get the a new url only having the dirname as the path :param str url: the url :return: the modified url with only dirname as path """ return split(url)[0]
[docs]def split(url): """ Split a url in a url with the dirname and the basename part of the path of the url :param str url: the url :return: a tuple with (dirname_url, basename) """ # pylint: disable=protected-access parsed_url = up.urlparse(str(url))._asdict() parsed_url['path'], part = posixpath.split(parsed_url['path']) return up.urlunparse(list(parsed_url.values())), part
[docs]def join(url, *p): """ Join the path in the url with p :param str url: the base url to join with :param p: additional parts of the path :return: the url with the parts added to the path """ # pylint: disable=protected-access parsed_url = up.urlparse(str(url))._asdict() parsed_url['path'] = posixpath.join(parsed_url['path'], *p) return up.urlunparse(list(parsed_url.values()))
[docs]def normurl(url): """ Normalized the path of the url :param str url: the url :return: the normalized url """ # pylint: disable=protected-access parsed_url = up.urlparse(str(url))._asdict() parsed_url['path'] = posixpath.normpath(parsed_url['path']) return up.urlunparse(list(parsed_url.values()))
[docs]def create_vfs_url(mountpoint, path): """ Construct an url from a given mount point and a relative path to the mount point. :param str mountpoint: the name of the mountpoint :param str path: relative path from the mountpoint :return: the created vfs url """ return "vfs://%s/%s" % (mountpoint, path.strip('/'))
[docs]def full_split(urlpath): """ Split the path in the url in a list of parts :param urlpath: the url path :return: a list of parts """ parts = [] while True: newpath, tail = posixpath.split(urlpath) if newpath == urlpath: assert not tail if urlpath: parts.append(urlpath) break parts.append(tail) urlpath = newpath parts.reverse() return parts
def _correct_separators(path): """ Translates the URL seperator '/' into the apropriate seperator for the OS :param str path: the path to correct :return: path with consistent separators """ return re.sub('/', ('%r' % os.path.sep).strip("'"), path.strip('/'))