"""Guess the MIME type of a file.
This module defines two useful functions:
guess_type(url) -- guess the MIME type and encoding of a URL.
guess_extension(type) -- guess the extension for a given MIME type.
It also contains the following, for tuning the behavior:
Data:
knownfiles -- list of files to parse
inited -- flag set when init() has been called
suffixes_map -- dictionary mapping suffixes to suffixes
encodings_map -- dictionary mapping suffixes to encodings
types_map -- dictionary mapping suffixes to types
Functions:
init([files]) -- parse a list of files, default knownfiles
read_mime_types(file) -- parse one file, return a dictionary or None
"""
import posixpath
import urllib
__all__ = ["guess_type","guess_extension","read_mime_types","init"]
knownfiles = [
"/usr/local/etc/httpd/conf/mime.types",
"/usr/local/lib/netscape/mime.types",
"/usr/local/etc/httpd/conf/mime.types", # Apache 1.2
"/usr/local/etc/mime.types", # Apache 1.3
]
inited = 0
def guess_type(url):
"""Guess the type of a file based on its URL.
Return value is a tuple (type, encoding) where type is None if the
type can't be guessed (no or unknown suffix) or a string of the
form type/subtype, usable for a MIME Content-type header; and
encoding is None for no encoding or the name of the program used
to encode (e.g. compress or gzip). The mappings are table
driven. Encoding suffixes are case sensitive; type suffixes are
first tried case sensitive, then case insensitive.
The suffixes .tgz, .taz and .tz (case sensitive!) are all mapped
to ".tar.gz". (This is table-driven too, using the dictionary
suffix_map).
"""
if not inited:
init()
scheme, url = urllib.splittype(url)
if scheme == 'data':
# syntax of data URLs:
# dataurl := "data:" [ mediatype ] [ ";base64" ] "," data
# mediatype := [ type "/" subtype ] *( ";" parameter )
# data := *urlchar
# parameter := attribute "=" value
# type/subtype defaults to "text/plain"
comma = url.find(',')
if comma < 0:
# bad data URL
return None, None
semi = url.find(';', 0, comma)
if semi >= 0:
type = url[:semi]
else:
type = url[:comma]
if '=' in type or '/' not in type:
type = 'text/plain'
return type, None # never compressed, so encoding is None
base, ext = posixpath.splitext(url)
while suffix_map.has_key(ext):
base, ext = posixpath.splitext(base + suffix_map[ext])
if encodings_map.has_key(ext):
encoding = encodings_map[ext]
base, ext = posixpath.splitext(base)
else:
encoding = None
if types_map.has_key(ext):
return types_map[ext], encoding
elif types_map.has_key(ext.lower()):
return types_map[ext.lower()], encoding
else:
return None, encoding
def guess_extension(type):
"""Guess the extension for a file based on its MIME type.
Return value is a string giving a filename extension, including the
leading dot ('.'). The extension is not guaranteed to have been
associated with any particular data stream, but would be mapped to the
MIME type `type' by guess_type(). If no extension can be guessed for
`type', None is returned.
"""
global inited
if not inited:
init()
type = type.lower()
for ext, stype in types_map.items():
if type == stype:
return ext
return None
def init(files=None):
global inited
for file in files or knownfiles:
s = read_mime_types(file)
if s:
for key, value in s.items():
types_map[key] = value
inited = 1
def read_mime_types(file):
try:
f = open(file)
except IOError:
return None
map = {}
while 1:
line = f.readline()
if not line: break
words = line.split()
for i in range(len(words)):
if words[i][0] == '#':
del words[i:]
break
if not words: continue
type, suffixes = words[0], words[1:]
for suff in suffixes:
map['.'+suff] = type
f.close()
return map
suffix_map = {
'.tgz': '.tar.gz',
'.taz': '.tar.gz',
'.tz': '.tar.gz',
}
encodings_map = {
'.gz': 'gzip',
'.Z': 'compress',
}
types_map = {
'.a': 'application/octet-stream',
'.ai': 'application/postscript',
'.aif': 'audio/x-aiff',
'.aifc': 'audio/x-aiff',
'.aiff': 'audio/x-aiff',
'.au': 'audio/basic',
'.avi': 'video/x-msvideo',
'.bcpio': 'application/x-bcpio',
'.bin': 'application/octet-stream',
'.cdf': 'application/x-netcdf',
'.cpio': 'application/x-cpio',
'.csh': 'application/x-csh',
'.dll': 'application/octet-stream',
'.dvi': 'application/x-dvi',
'.exe': 'application/octet-stream',
'.eps': 'application/postscript',
'.etx': 'text/x-setext',
'.gif': 'image/gif',
'.gtar': 'application/x-gtar',
'.hdf': 'application/x-hdf',
'.htm': 'text/html',
'.html': 'text/html',
'.ief': 'image/ief',
'.jpe': 'image/jpeg',
'.jpeg': 'image/jpeg',
'.jpg': 'image/jpeg',
'.js': 'application/x-javascript',
'.latex': 'application/x-latex',
'.man': 'application/x-troff-man',
'.me': 'application/x-troff-me',
'.mif': 'application/x-mif',
'.mov': 'video/quicktime',
'.movie': 'video/x-sgi-movie',
'.mpe': 'video/mpeg',
'.mpeg': 'video/mpeg',
'.mpg': 'video/mpeg',
'.ms': 'application/x-troff-ms',
'.nc': 'application/x-netcdf',
'.o': 'application/octet-stream',
'.obj': 'application/octet-stream',
'.oda': 'application/oda',
'.pbm': 'image/x-portable-bitmap',
'.pdf': 'application/pdf',
'.pgm': 'image/x-portable-graymap',
'.pnm': 'image/x-portable-anymap',
'.png': 'image/png',
'.ppm': 'image/x-portable-pixmap',
'.py': 'text/x-python',
'.pyc': 'application/x-python-code',
'.ps': 'application/postscript',
'.qt': 'video/quicktime',
'.ras': 'image/x-cmu-raster',
'.rgb': 'image/x-rgb',
'.rdf': 'application/xml',
'.roff': 'application/x-troff',
'.rtf': 'application/rtf',
'.rtx': 'text/richtext',
'.sgm': 'text/x-sgml',
'.sgml': 'text/x-sgml',
'.sh': 'application/x-sh',
'.shar': 'application/x-shar',
'.snd': 'audio/basic',
'.so': 'application/octet-stream',
'.src': 'application/x-wais-source',
'.sv4cpio': 'application/x-sv4cpio',
'.sv4crc': 'application/x-sv4crc',
'.t': 'application/x-troff',
'.tar': 'application/x-tar',
'.tcl': 'application/x-tcl',
'.tex': 'application/x-tex',
'.texi': 'application/x-texinfo',
'.texinfo': 'application/x-texinfo',
'.tif': 'image/tiff',
'.tiff': 'image/tiff',
'.tr': 'application/x-troff',
'.tsv': 'text/tab-separated-values',
'.txt': 'text/plain',
'.ustar': 'application/x-ustar',
'.wav': 'audio/x-wav',
'.xbm': 'image/x-xbitmap',
'.xml': 'text/xml',
'.xsl': 'application/xml',
'.xpm': 'image/x-xpixmap',
'.xwd': 'image/x-xwindowdump',
'.zip': 'application/zip',
}
if __name__ == '__main__':
import sys
print guess_type(sys.argv[1])
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