"""Guess the MIME type of a file.
This module defines two useful functions:
guess_type(url, strict=True) -- guess the MIME type and encoding of a URL.
guess_extension(type, strict=True) -- 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
suffix_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 (on Windows, the
default values are taken from the registry)
read_mime_types(file) -- parse one file, return a dictionary or None
"""
import os
import sys
import posixpath
import urllib.parse
try:
import winreg as _winreg
except ImportError:
_winreg = None
__all__ = [
"guess_type","guess_extension","guess_all_extensions",
"add_type","read_mime_types","init"
]
knownfiles = [
"/etc/mime.types",
"/etc/httpd/mime.types", # Mac OS X
"/etc/httpd/conf/mime.types", # Apache
"/etc/apache/mime.types", # Apache 1
"/etc/apache2/mime.types", # Apache 2
"/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 = False
_db = None
class MimeTypes:
"""MIME-types datastore.
This datastore can handle information from mime.types-style files
and supports basic determination of MIME type from a filename or
URL, and can guess a reasonable extension given a MIME type.
"""
def __init__(self, filenames=(), strict=True):
if not inited:
init()
self.encodings_map = encodings_map.copy()
self.suffix_map = suffix_map.copy()
self.types_map = ({}, {}) # dict for (non-strict, strict)
self.types_map_inv = ({}, {})
for (ext, type) in types_map.items():
self.add_type(type, ext, True)
for (ext, type) in common_types.items():
self.add_type(type, ext, False)
for name in filenames:
self.read(name, strict)
def add_type(self, type, ext, strict=True):
"""Add a mapping between a type and an extension.
When the extension is already known, the new
type will replace the old one. When the type
is already known the extension will be added
to the list of known extensions.
If strict is true, information will be added to
list of standard types, else to the list of non-standard
types.
"""
self.types_map[strict][ext] = type
exts = self.types_map_inv[strict].setdefault(type, [])
if ext not in exts:
exts.append(ext)
def guess_type(self, url, strict=True):
"""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.)
Optional `strict' argument when False adds a bunch of commonly found,
but non-standard types.
"""
scheme, url = urllib.parse.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 ext in self.suffix_map:
base, ext = posixpath.splitext(base + self.suffix_map[ext])
if ext in self.encodings_map:
encoding = self.encodings_map[ext]
base, ext = posixpath.splitext(base)
else:
encoding = None
types_map = self.types_map[True]
if ext in types_map:
return types_map[ext], encoding
elif ext.lower() in types_map:
return types_map[ext.lower()], encoding
elif strict:
return None, encoding
types_map = self.types_map[False]
if ext in types_map:
return types_map[ext], encoding
elif ext.lower() in types_map:
return types_map[ext.lower()], encoding
else:
return None, encoding
def guess_all_extensions(self, type, strict=True):
"""Guess the extensions for a file based on its MIME type.
Return value is a list of strings giving the possible filename
extensions, 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().
Optional `strict' argument when false adds a bunch of commonly found,
but non-standard types.
"""
type = type.lower()
extensions = self.types_map_inv[True].get(type, [])
if not strict:
for ext in self.types_map_inv[False].get(type, []):
if ext not in extensions:
extensions.append(ext)
return extensions
def guess_extension(self, type, strict=True):
"""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.
Optional `strict' argument when false adds a bunch of commonly found,
but non-standard types.
"""
extensions = self.guess_all_extensions(type, strict)
if not extensions:
return None
return extensions[0]
def read(self, filename, strict=True):
"""
Read a single mime.types-format file, specified by pathname.
If strict is true, information will be added to
list of standard types, else to the list of non-standard
types.
"""
with open(filename, encoding='utf-8') as fp:
self.readfp(fp, strict)
def readfp(self, fp, strict=True):
"""
Read a single mime.types-format file.
If strict is true, information will be added to
list of standard types, else to the list of non-standard
types.
"""
while 1:
line = fp.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:
self.add_type(type, '.' + suff, strict)
def read_windows_registry(self, strict=True):
"""
Load the MIME types database from Windows registry.
If strict is true, information will be added to
list of standard types, else to the list of non-standard
types.
"""
# Windows only
if not _winreg:
return
def enum_types(mimedb):
i = 0
while True:
try:
ctype = _winreg.EnumKey(mimedb, i)
except EnvironmentError:
break
else:
yield ctype
i += 1
with _winreg.OpenKey(_winreg.HKEY_CLASSES_ROOT, '') as hkcr:
for subkeyname in enum_types(hkcr):
try:
with _winreg.OpenKey(hkcr, subkeyname) as subkey:
# Only check file extensions
if not subkeyname.startswith("."):
continue
# raises EnvironmentError if no 'Content Type' value
mimetype, datatype = _winreg.QueryValueEx(
subkey, 'Content Type')
if datatype != _winreg.REG_SZ:
continue
self.add_type(mimetype, subkeyname, strict)
except EnvironmentError:
continue
def guess_type(url, strict=True):
"""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).
Optional `strict' argument when false adds a bunch of commonly found, but
non-standard types.
"""
if _db is None:
init()
return _db.guess_type(url, strict)
def guess_all_extensions(type, strict=True):
"""Guess the extensions for a file based on its MIME type.
Return value is a list of strings giving the possible filename
extensions, 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.
Optional `strict' argument when false adds a bunch of commonly found,
but non-standard types.
"""
if _db is None:
init()
return _db.guess_all_extensions(type, strict)
def guess_extension(type, strict=True):
"""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.
Optional `strict' argument when false adds a bunch of commonly found,
but non-standard types.
"""
if _db is None:
init()
return _db.guess_extension(type, strict)
def add_type(type, ext, strict=True):
"""Add a mapping between a type and an extension.
When the extension is already known, the new
type will replace the old one. When the type
is already known the extension will be added
to the list of known extensions.
If strict is true, information will be added to
list of standard types, else to the list of non-standard
types.
"""
if _db is None:
init()
return _db.add_type(type, ext, strict)
def init(files=None):
global suffix_map, types_map, encodings_map, common_types
global inited, _db
inited = True # so that MimeTypes.__init__() doesn't call us again
db = MimeTypes()
if files is None:
if _winreg:
db.read_windows_registry()
files = knownfiles
for file in files:
if os.path.isfile(file):
db.read(file)
encodings_map = db.encodings_map
suffix_map = db.suffix_map
types_map = db.types_map[True]
common_types = db.types_map[False]
# Make the DB a global variable now that it is fully initialized
_db = db
def read_mime_types(file):
try:
f = open(file)
except IOError:
return None
with f:
db = MimeTypes()
db.readfp(f, True)
return db.types_map[True]
def _default_mime_types():
global suffix_map
global encodings_map
global types_map
global common_types
suffix_map = {
'.svgz': '.svg.gz',
'.tgz': '.tar.gz',
'.taz': '.tar.gz',
'.tz': '.tar.gz',
'.tbz2': '.tar.bz2',
'.txz': '.tar.xz',
}
encodings_map = {
'.gz': 'gzip',
'.Z': 'compress',
'.bz2': 'bzip2',
'.xz': 'xz',
}
# Before adding new types, make sure they are either registered with IANA,
# at http://www.iana.org/assignments/media-types
# or extensions, i.e. using the x- prefix
# If you add to these, please keep them sorted!
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',
'.bat' : 'text/plain',
'.bcpio' : 'application/x-bcpio',
'.bin' : 'application/octet-stream',
'.bmp' : 'image/x-ms-bmp',
'.c' : 'text/plain',
# Duplicates :(
'.cdf' : 'application/x-cdf',
'.cdf' : 'application/x-netcdf',
'.cpio' : 'application/x-cpio',
'.csh' : 'application/x-csh',
'.css' : 'text/css',
'.dll' : 'application/octet-stream',
'.doc' : 'application/msword',
'.dot' : 'application/msword',
'.dvi' : 'application/x-dvi',
'.eml' : 'message/rfc822',
'.eps' : 'application/postscript',
'.etx' : 'text/x-setext',
'.exe' : 'application/octet-stream',
'.gif' : 'image/gif',
'.gtar' : 'application/x-gtar',
'.h' : 'text/plain',
'.hdf' : 'application/x-hdf',
'.htm' : 'text/html',
'.html' : 'text/html',
'.ico' : 'image/vnd.microsoft.icon',
'.ief' : 'image/ief',
'.jpe' : 'image/jpeg',
'.jpeg' : 'image/jpeg',
'.jpg' : 'image/jpeg',
'.js' : 'application/javascript',
'.ksh' : 'text/plain',
'.latex' : 'application/x-latex',
'.m1v' : 'video/mpeg',
'.m3u' : 'application/vnd.apple.mpegurl',
'.m3u8' : 'application/vnd.apple.mpegurl',
'.man' : 'application/x-troff-man',
'.me' : 'application/x-troff-me',
'.mht' : 'message/rfc822',
'.mhtml' : 'message/rfc822',
'.mif' : 'application/x-mif',
'.mov' : 'video/quicktime',
'.movie' : 'video/x-sgi-movie',
'.mp2' : 'audio/mpeg',
'.mp3' : 'audio/mpeg',
'.mp4' : 'video/mp4',
'.mpa' : 'video/mpeg',
'.mpe' : 'video/mpeg',
'.mpeg' : 'video/mpeg',
'.mpg' : 'video/mpeg',
'.ms' : 'application/x-troff-ms',
'.nc' : 'application/x-netcdf',
'.nws' : 'message/rfc822',
'.o' : 'application/octet-stream',
'.obj' : 'application/octet-stream',
'.oda' : 'application/oda',
'.p12' : 'application/x-pkcs12',
'.p7c' : 'application/pkcs7-mime',
'.pbm' : 'image/x-portable-bitmap',
'.pdf' : 'application/pdf',
'.pfx' : 'application/x-pkcs12',
'.pgm' : 'image/x-portable-graymap',
'.pl' : 'text/plain',
'.png' : 'image/png',
'.pnm' : 'image/x-portable-anymap',
'.pot' : 'application/vnd.ms-powerpoint',
'.ppa' : 'application/vnd.ms-powerpoint',
'.ppm' : 'image/x-portable-pixmap',
'.pps' : 'application/vnd.ms-powerpoint',
'.ppt' : 'application/vnd.ms-powerpoint',
'.ps' : 'application/postscript',
'.pwz' : 'application/vnd.ms-powerpoint',
'.py' : 'text/x-python',
'.pyc' : 'application/x-python-code',
'.pyo' : 'application/x-python-code',
'.qt' : 'video/quicktime',
'.ra' : 'audio/x-pn-realaudio',
'.ram' : 'application/x-pn-realaudio',
'.ras' : 'image/x-cmu-raster',
'.rdf' : 'application/xml',
'.rgb' : 'image/x-rgb',
'.roff' : 'application/x-troff',
'.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',
'.svg' : 'image/svg+xml',
'.swf' : 'application/x-shockwave-flash',
'.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',
'.vcf' : 'text/x-vcard',
'.wav' : 'audio/x-wav',
'.wiz' : 'application/msword',
'.wsdl' : 'application/xml',
'.xbm' : 'image/x-xbitmap',
'.xlb' : 'application/vnd.ms-excel',
# Duplicates :(
'.xls' : 'application/excel',
'.xls' : 'application/vnd.ms-excel',
'.xml' : 'text/xml',
'.xpdl' : 'application/xml',
'.xpm' : 'image/x-xpixmap',
'.xsl' : 'application/xml',
'.xwd' : 'image/x-xwindowdump',
'.zip' : 'application/zip',
}
# These are non-standard types, commonly found in the wild. They will
# only match if strict=0 flag is given to the API methods.
# Please sort these too
common_types = {
'.jpg' : 'image/jpg',
'.mid' : 'audio/midi',
'.midi': 'audio/midi',
'.pct' : 'image/pict',
'.pic' : 'image/pict',
'.pict': 'image/pict',
'.rtf' : 'application/rtf',
'.xul' : 'text/xul'
}
_default_mime_types()
if __name__ == '__main__':
import getopt
USAGE = """\
Usage: mimetypes.py [options] type
Options:
--help / -h -- print this message and exit
--lenient / -l -- additionally search of some common, but non-standard
types.
--extension / -e -- guess extension instead of type
More than one type argument may be given.
"""
def usage(code, msg=''):
print(USAGE)
if msg: print(msg)
sys.exit(code)
try:
opts, args = getopt.getopt(sys.argv[1:], 'hle',
['help', 'lenient', 'extension'])
except getopt.error as msg:
usage(1, msg)
strict = 1
extension = 0
for opt, arg in opts:
if opt in ('-h', '--help'):
usage(0)
elif opt in ('-l', '--lenient'):
strict = 0
elif opt in ('-e', '--extension'):
extension = 1
for gtype in args:
if extension:
guess = guess_extension(gtype, strict)
if not guess: print("I don't know anything about type", gtype)
else: print(guess)
else:
guess, encoding = guess_type(gtype, strict)
if not guess: print("I don't know anything about type", gtype)
else: print('type:', guess, 'encoding:', encoding)
