Mercurial > repos > shellac > guppy_basecaller
view env/lib/python3.7/site-packages/requests_toolbelt/downloadutils/stream.py @ 0:26e78fe6e8c4 draft
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
author | shellac |
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date | Sat, 02 May 2020 07:14:21 -0400 |
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# -*- coding: utf-8 -*- """Utilities for dealing with streamed requests.""" import collections import os.path import re from .. import exceptions as exc # Regular expressions stolen from werkzeug/http.py # cd2c97bb0a076da2322f11adce0b2731f9193396 L62-L64 _QUOTED_STRING_RE = r'"[^"\\]*(?:\\.[^"\\]*)*"' _OPTION_HEADER_PIECE_RE = re.compile( r';\s*(%s|[^\s;=]+)\s*(?:=\s*(%s|[^;]+))?\s*' % (_QUOTED_STRING_RE, _QUOTED_STRING_RE) ) _DEFAULT_CHUNKSIZE = 512 def _get_filename(content_disposition): for match in _OPTION_HEADER_PIECE_RE.finditer(content_disposition): k, v = match.groups() if k == 'filename': # ignore any directory paths in the filename return os.path.split(v)[1] return None def get_download_file_path(response, path): """ Given a response and a path, return a file path for a download. If a ``path`` parameter is a directory, this function will parse the ``Content-Disposition`` header on the response to determine the name of the file as reported by the server, and return a file path in the specified directory. If ``path`` is empty or None, this function will return a path relative to the process' current working directory. If path is a full file path, return it. :param response: A Response object from requests :type response: requests.models.Response :param str path: Directory or file path. :returns: full file path to download as :rtype: str :raises: :class:`requests_toolbelt.exceptions.StreamingError` """ path_is_dir = path and os.path.isdir(path) if path and not path_is_dir: # fully qualified file path filepath = path else: response_filename = _get_filename( response.headers.get('content-disposition', '') ) if not response_filename: raise exc.StreamingError('No filename given to stream response to') if path_is_dir: # directory to download to filepath = os.path.join(path, response_filename) else: # fallback to downloading to current working directory filepath = response_filename return filepath def stream_response_to_file(response, path=None, chunksize=_DEFAULT_CHUNKSIZE): """Stream a response body to the specified file. Either use the ``path`` provided or use the name provided in the ``Content-Disposition`` header. .. warning:: If you pass this function an open file-like object as the ``path`` parameter, the function will not close that file for you. .. warning:: This function will not automatically close the response object passed in as the ``response`` parameter. If a ``path`` parameter is a directory, this function will parse the ``Content-Disposition`` header on the response to determine the name of the file as reported by the server, and return a file path in the specified directory. If no ``path`` parameter is supplied, this function will default to the process' current working directory. .. code-block:: python import requests from requests_toolbelt import exceptions from requests_toolbelt.downloadutils import stream r = requests.get(url, stream=True) try: filename = stream.stream_response_to_file(r) except exceptions.StreamingError as e: # The toolbelt could not find the filename in the # Content-Disposition print(e.message) You can also specify the filename as a string. This will be passed to the built-in :func:`open` and we will read the content into the file. .. code-block:: python import requests from requests_toolbelt.downloadutils import stream r = requests.get(url, stream=True) filename = stream.stream_response_to_file(r, path='myfile') If the calculated download file path already exists, this function will raise a StreamingError. Instead, if you want to manage the file object yourself, you need to provide either a :class:`io.BytesIO` object or a file opened with the `'b'` flag. See the two examples below for more details. .. code-block:: python import requests from requests_toolbelt.downloadutils import stream with open('myfile', 'wb') as fd: r = requests.get(url, stream=True) filename = stream.stream_response_to_file(r, path=fd) print('{0} saved to {1}'.format(url, filename)) .. code-block:: python import io import requests from requests_toolbelt.downloadutils import stream b = io.BytesIO() r = requests.get(url, stream=True) filename = stream.stream_response_to_file(r, path=b) assert filename is None :param response: A Response object from requests :type response: requests.models.Response :param path: *(optional)*, Either a string with the path to the location to save the response content, or a file-like object expecting bytes. :type path: :class:`str`, or object with a :meth:`write` :param int chunksize: (optional), Size of chunk to attempt to stream (default 512B). :returns: The name of the file, if one can be determined, else None :rtype: str :raises: :class:`requests_toolbelt.exceptions.StreamingError` """ pre_opened = False fd = None filename = None if path and isinstance(getattr(path, 'write', None), collections.Callable): pre_opened = True fd = path filename = getattr(fd, 'name', None) else: filename = get_download_file_path(response, path) if os.path.exists(filename): raise exc.StreamingError("File already exists: %s" % filename) fd = open(filename, 'wb') for chunk in response.iter_content(chunk_size=chunksize): fd.write(chunk) if not pre_opened: fd.close() return filename