1 :mod:`mimetypes` --- Map filenames to MIME types 2 ================================================ 3 4 .. module:: mimetypes 5 :synopsis: Mapping of filename extensions to MIME types. 6 7 .. sectionauthor:: Fred L. Drake, Jr. <fdrake (a] acm.org> 8 9 **Source code:** :source:`Lib/mimetypes.py` 10 11 .. index:: pair: MIME; content type 12 13 -------------- 14 15 The :mod:`mimetypes` module converts between a filename or URL and the MIME type 16 associated with the filename extension. Conversions are provided from filename 17 to MIME type and from MIME type to filename extension; encodings are not 18 supported for the latter conversion. 19 20 The module provides one class and a number of convenience functions. The 21 functions are the normal interface to this module, but some applications may be 22 interested in the class as well. 23 24 The functions described below provide the primary interface for this module. If 25 the module has not been initialized, they will call :func:`init` if they rely on 26 the information :func:`init` sets up. 27 28 29 .. function:: guess_type(url, strict=True) 30 31 .. index:: pair: MIME; headers 32 33 Guess the type of a file based on its filename or URL, given by *url*. The 34 return value is a tuple ``(type, encoding)`` where *type* is ``None`` if the 35 type can't be guessed (missing or unknown suffix) or a string of the form 36 ``'type/subtype'``, usable for a MIME :mailheader:`content-type` header. 37 38 *encoding* is ``None`` for no encoding or the name of the program used to encode 39 (e.g. :program:`compress` or :program:`gzip`). The encoding is suitable for use 40 as a :mailheader:`Content-Encoding` header, **not** as a 41 :mailheader:`Content-Transfer-Encoding` header. The mappings are table driven. 42 Encoding suffixes are case sensitive; type suffixes are first tried case 43 sensitively, then case insensitively. 44 45 The optional *strict* argument is a flag specifying whether the list of known MIME types 46 is limited to only the official types `registered with IANA 47 <https://www.iana.org/assignments/media-types/media-types.xhtml>`_. 48 When *strict* is ``True`` (the default), only the IANA types are supported; when 49 *strict* is ``False``, some additional non-standard but commonly used MIME types 50 are also recognized. 51 52 53 .. function:: guess_all_extensions(type, strict=True) 54 55 Guess the extensions for a file based on its MIME type, given by *type*. The 56 return value is a list of strings giving all possible filename extensions, 57 including the leading dot (``'.'``). The extensions are not guaranteed to have 58 been associated with any particular data stream, but would be mapped to the MIME 59 type *type* by :func:`guess_type`. 60 61 The optional *strict* argument has the same meaning as with the :func:`guess_type` function. 62 63 64 .. function:: guess_extension(type, strict=True) 65 66 Guess the extension for a file based on its MIME type, given by *type*. The 67 return value is a string giving a filename extension, including the leading dot 68 (``'.'``). The extension is not guaranteed to have been associated with any 69 particular data stream, but would be mapped to the MIME type *type* by 70 :func:`guess_type`. If no extension can be guessed for *type*, ``None`` is 71 returned. 72 73 The optional *strict* argument has the same meaning as with the :func:`guess_type` function. 74 75 Some additional functions and data items are available for controlling the 76 behavior of the module. 77 78 79 .. function:: init(files=None) 80 81 Initialize the internal data structures. If given, *files* must be a sequence 82 of file names which should be used to augment the default type map. If omitted, 83 the file names to use are taken from :const:`knownfiles`; on Windows, the 84 current registry settings are loaded. Each file named in *files* or 85 :const:`knownfiles` takes precedence over those named before it. Calling 86 :func:`init` repeatedly is allowed. 87 88 Specifying an empty list for *files* will prevent the system defaults from 89 being applied: only the well-known values will be present from a built-in list. 90 91 .. versionchanged:: 3.2 92 Previously, Windows registry settings were ignored. 93 94 95 .. function:: read_mime_types(filename) 96 97 Load the type map given in the file *filename*, if it exists. The type map is 98 returned as a dictionary mapping filename extensions, including the leading dot 99 (``'.'``), to strings of the form ``'type/subtype'``. If the file *filename* 100 does not exist or cannot be read, ``None`` is returned. 101 102 103 .. function:: add_type(type, ext, strict=True) 104 105 Add a mapping from the MIME type *type* to the extension *ext*. When the 106 extension is already known, the new type will replace the old one. When the type 107 is already known the extension will be added to the list of known extensions. 108 109 When *strict* is ``True`` (the default), the mapping will be added to the 110 official MIME types, otherwise to the non-standard ones. 111 112 113 .. data:: inited 114 115 Flag indicating whether or not the global data structures have been initialized. 116 This is set to ``True`` by :func:`init`. 117 118 119 .. data:: knownfiles 120 121 .. index:: single: file; mime.types 122 123 List of type map file names commonly installed. These files are typically named 124 :file:`mime.types` and are installed in different locations by different 125 packages. 126 127 128 .. data:: suffix_map 129 130 Dictionary mapping suffixes to suffixes. This is used to allow recognition of 131 encoded files for which the encoding and the type are indicated by the same 132 extension. For example, the :file:`.tgz` extension is mapped to :file:`.tar.gz` 133 to allow the encoding and type to be recognized separately. 134 135 136 .. data:: encodings_map 137 138 Dictionary mapping filename extensions to encoding types. 139 140 141 .. data:: types_map 142 143 Dictionary mapping filename extensions to MIME types. 144 145 146 .. data:: common_types 147 148 Dictionary mapping filename extensions to non-standard, but commonly found MIME 149 types. 150 151 152 An example usage of the module:: 153 154 >>> import mimetypes 155 >>> mimetypes.init() 156 >>> mimetypes.knownfiles 157 ['/etc/mime.types', '/etc/httpd/mime.types', ... ] 158 >>> mimetypes.suffix_map['.tgz'] 159 '.tar.gz' 160 >>> mimetypes.encodings_map['.gz'] 161 'gzip' 162 >>> mimetypes.types_map['.tgz'] 163 'application/x-tar-gz' 164 165 166 .. _mimetypes-objects: 167 168 MimeTypes Objects 169 ----------------- 170 171 The :class:`MimeTypes` class may be useful for applications which may want more 172 than one MIME-type database; it provides an interface similar to the one of the 173 :mod:`mimetypes` module. 174 175 176 .. class:: MimeTypes(filenames=(), strict=True) 177 178 This class represents a MIME-types database. By default, it provides access to 179 the same database as the rest of this module. The initial database is a copy of 180 that provided by the module, and may be extended by loading additional 181 :file:`mime.types`\ -style files into the database using the :meth:`read` or 182 :meth:`readfp` methods. The mapping dictionaries may also be cleared before 183 loading additional data if the default data is not desired. 184 185 The optional *filenames* parameter can be used to cause additional files to be 186 loaded "on top" of the default database. 187 188 189 .. attribute:: MimeTypes.suffix_map 190 191 Dictionary mapping suffixes to suffixes. This is used to allow recognition of 192 encoded files for which the encoding and the type are indicated by the same 193 extension. For example, the :file:`.tgz` extension is mapped to :file:`.tar.gz` 194 to allow the encoding and type to be recognized separately. This is initially a 195 copy of the global :data:`suffix_map` defined in the module. 196 197 198 .. attribute:: MimeTypes.encodings_map 199 200 Dictionary mapping filename extensions to encoding types. This is initially a 201 copy of the global :data:`encodings_map` defined in the module. 202 203 204 .. attribute:: MimeTypes.types_map 205 206 Tuple containing two dictionaries, mapping filename extensions to MIME types: 207 the first dictionary is for the non-standards types and the second one is for 208 the standard types. They are initialized by :data:`common_types` and 209 :data:`types_map`. 210 211 212 .. attribute:: MimeTypes.types_map_inv 213 214 Tuple containing two dictionaries, mapping MIME types to a list of filename 215 extensions: the first dictionary is for the non-standards types and the 216 second one is for the standard types. They are initialized by 217 :data:`common_types` and :data:`types_map`. 218 219 220 .. method:: MimeTypes.guess_extension(type, strict=True) 221 222 Similar to the :func:`guess_extension` function, using the tables stored as part 223 of the object. 224 225 226 .. method:: MimeTypes.guess_type(url, strict=True) 227 228 Similar to the :func:`guess_type` function, using the tables stored as part of 229 the object. 230 231 232 .. method:: MimeTypes.guess_all_extensions(type, strict=True) 233 234 Similar to the :func:`guess_all_extensions` function, using the tables stored 235 as part of the object. 236 237 238 .. method:: MimeTypes.read(filename, strict=True) 239 240 Load MIME information from a file named *filename*. This uses :meth:`readfp` to 241 parse the file. 242 243 If *strict* is ``True``, information will be added to list of standard types, 244 else to the list of non-standard types. 245 246 247 .. method:: MimeTypes.readfp(fp, strict=True) 248 249 Load MIME type information from an open file *fp*. The file must have the format of 250 the standard :file:`mime.types` files. 251 252 If *strict* is ``True``, information will be added to the list of standard 253 types, else to the list of non-standard types. 254 255 256 .. method:: MimeTypes.read_windows_registry(strict=True) 257 258 Load MIME type information from the Windows registry. Availability: Windows. 259 260 If *strict* is ``True``, information will be added to the list of standard 261 types, else to the list of non-standard types. 262 263 .. versionadded:: 3.2 264
