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Diffstat (limited to 'lib/mimeparse/mimeparse.py')
| -rw-r--r-- | lib/mimeparse/mimeparse.py | 167 |
1 files changed, 0 insertions, 167 deletions
diff --git a/lib/mimeparse/mimeparse.py b/lib/mimeparse/mimeparse.py deleted file mode 100644 index 7fb4e43477..0000000000 --- a/lib/mimeparse/mimeparse.py +++ /dev/null @@ -1,167 +0,0 @@ -"""MIME-Type Parser - -This module provides basic functions for handling mime-types. It can handle -matching mime-types against a list of media-ranges. See section 14.1 of the -HTTP specification [RFC 2616] for a complete explanation. - - http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1 - -Contents: - - parse_mime_type(): Parses a mime-type into its component parts. - - parse_media_range(): Media-ranges are mime-types with wild-cards and a 'q' - quality parameter. - - quality(): Determines the quality ('q') of a mime-type when - compared against a list of media-ranges. - - quality_parsed(): Just like quality() except the second parameter must be - pre-parsed. - - best_match(): Choose the mime-type with the highest quality ('q') - from a list of candidates. -""" - -__version__ = '0.1.3' -__author__ = 'Joe Gregorio' -__email__ = 'joe@bitworking.org' -__license__ = 'MIT License' -__credits__ = '' - - -def parse_mime_type(mime_type): - """Parses a mime-type into its component parts. - - Carves up a mime-type and returns a tuple of the (type, subtype, params) - where 'params' is a dictionary of all the parameters for the media range. - For example, the media range 'application/xhtml;q=0.5' would get parsed - into: - - ('application', 'xhtml', {'q', '0.5'}) - """ - parts = mime_type.split(';') - params = dict([tuple([s.strip() for s in param.split('=', 1)])\ - for param in parts[1:] - ]) - full_type = parts[0].strip() - # Java URLConnection class sends an Accept header that includes a - # single '*'. Turn it into a legal wildcard. - if full_type == '*': - full_type = '*/*' - (type, subtype) = full_type.split('/') - - return (type.strip(), subtype.strip(), params) - - -def parse_media_range(range): - """Parse a media-range into its component parts. - - Carves up a media range and returns a tuple of the (type, subtype, - params) where 'params' is a dictionary of all the parameters for the media - range. For example, the media range 'application/*;q=0.5' would get parsed - into: - - ('application', '*', {'q', '0.5'}) - - In addition this function also guarantees that there is a value for 'q' - in the params dictionary, filling it in with a proper default if - necessary. - """ - (type, subtype, params) = parse_mime_type(range) - if 'q' not in params or not params['q'] or \ - not float(params['q']) or float(params['q']) > 1\ - or float(params['q']) < 0: - params['q'] = '1' - - return (type, subtype, params) - - -def fitness_and_quality_parsed(mime_type, parsed_ranges): - """Find the best match for a mime-type amongst parsed media-ranges. - - Find the best match for a given mime-type against a list of media_ranges - that have already been parsed by parse_media_range(). Returns a tuple of - the fitness value and the value of the 'q' quality parameter of the best - match, or (-1, 0) if no match was found. Just as for quality_parsed(), - 'parsed_ranges' must be a list of parsed media ranges. - """ - best_fitness = -1 - best_fit_q = 0 - (target_type, target_subtype, target_params) =\ - parse_media_range(mime_type) - for (type, subtype, params) in parsed_ranges: - type_match = (type == target_type or\ - type == '*' or\ - target_type == '*') - subtype_match = (subtype == target_subtype or\ - subtype == '*' or\ - target_subtype == '*') - if type_match and subtype_match: - param_matches = sum([1 for (key, value) in \ - target_params.items() if key != 'q' and \ - key in params and value == params[key]], 0) - fitness = (type == target_type) and 100 or 0 - fitness += (subtype == target_subtype) and 10 or 0 - fitness += param_matches - if fitness > best_fitness: - best_fitness = fitness - best_fit_q = params['q'] - - return best_fitness, float(best_fit_q) - - -def quality_parsed(mime_type, parsed_ranges): - """Find the best match for a mime-type amongst parsed media-ranges. - - Find the best match for a given mime-type against a list of media_ranges - that have already been parsed by parse_media_range(). Returns the 'q' - quality parameter of the best match, 0 if no match was found. This function - bahaves the same as quality() except that 'parsed_ranges' must be a list of - parsed media ranges. """ - - return fitness_and_quality_parsed(mime_type, parsed_ranges)[1] - - -def quality(mime_type, ranges): - """Return the quality ('q') of a mime-type against a list of media-ranges. - - Returns the quality 'q' of a mime-type when compared against the - media-ranges in ranges. For example: - - >>> quality('text/html','text/*;q=0.3, text/html;q=0.7, - text/html;level=1, text/html;level=2;q=0.4, */*;q=0.5') - 0.7 - - """ - parsed_ranges = [parse_media_range(r) for r in ranges.split(',')] - - return quality_parsed(mime_type, parsed_ranges) - - -def best_match(supported, header): - """Return mime-type with the highest quality ('q') from list of candidates. - - Takes a list of supported mime-types and finds the best match for all the - media-ranges listed in header. The value of header must be a string that - conforms to the format of the HTTP Accept: header. The value of 'supported' - is a list of mime-types. The list of supported mime-types should be sorted - in order of increasing desirability, in case of a situation where there is - a tie. - - >>> best_match(['application/xbel+xml', 'text/xml'], - 'text/*;q=0.5,*/*; q=0.1') - 'text/xml' - """ - split_header = _filter_blank(header.split(',')) - parsed_header = [parse_media_range(r) for r in split_header] - weighted_matches = [] - pos = 0 - for mime_type in supported: - weighted_matches.append((fitness_and_quality_parsed(mime_type, - parsed_header), pos, mime_type)) - pos += 1 - weighted_matches.sort() - - return weighted_matches[-1][0][1] and weighted_matches[-1][2] or '' - - -def _filter_blank(i): - for s in i: - if s.strip(): - yield s |