2
:mod:`mimetypes` --- Map filenames to MIME types
3
================================================
6
:synopsis: Mapping of filename extensions to MIME types.
7
.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
10
.. index:: pair: MIME; content type
12
The :mod:`mimetypes` module converts between a filename or URL and the MIME type
13
associated with the filename extension. Conversions are provided from filename
14
to MIME type and from MIME type to filename extension; encodings are not
15
supported for the latter conversion.
17
The module provides one class and a number of convenience functions. The
18
functions are the normal interface to this module, but some applications may be
19
interested in the class as well.
21
The functions described below provide the primary interface for this module. If
22
the module has not been initialized, they will call :func:`init` if they rely on
23
the information :func:`init` sets up.
26
.. function:: guess_type(filename[, strict])
28
.. index:: pair: MIME; headers
30
Guess the type of a file based on its filename or URL, given by *filename*. The
31
return value is a tuple ``(type, encoding)`` where *type* is ``None`` if the
32
type can't be guessed (missing or unknown suffix) or a string of the form
33
``'type/subtype'``, usable for a MIME :mailheader:`content-type` header.
35
*encoding* is ``None`` for no encoding or the name of the program used to encode
36
(e.g. :program:`compress` or :program:`gzip`). The encoding is suitable for use
37
as a :mailheader:`Content-Encoding` header, *not* as a
38
:mailheader:`Content-Transfer-Encoding` header. The mappings are table driven.
39
Encoding suffixes are case sensitive; type suffixes are first tried case
40
sensitively, then case insensitively.
42
Optional *strict* is a flag specifying whether the list of known MIME types
43
is limited to only the official types `registered with IANA
44
<http://www.iana.org/assignments/media-types/>`_ are recognized.
45
When *strict* is true (the default), only the IANA types are supported; when
46
*strict* is false, some additional non-standard but commonly used MIME types
50
.. function:: guess_all_extensions(type[, strict])
52
Guess the extensions for a file based on its MIME type, given by *type*. The
53
return value is a list of strings giving all possible filename extensions,
54
including the leading dot (``'.'``). The extensions are not guaranteed to have
55
been associated with any particular data stream, but would be mapped to the MIME
56
type *type* by :func:`guess_type`.
58
Optional *strict* has the same meaning as with the :func:`guess_type` function.
61
.. function:: guess_extension(type[, strict])
63
Guess the extension for a file based on its MIME type, given by *type*. The
64
return value is a string giving a filename extension, including the leading dot
65
(``'.'``). The extension is not guaranteed to have been associated with any
66
particular data stream, but would be mapped to the MIME type *type* by
67
:func:`guess_type`. If no extension can be guessed for *type*, ``None`` is
70
Optional *strict* has the same meaning as with the :func:`guess_type` function.
72
Some additional functions and data items are available for controlling the
73
behavior of the module.
76
.. function:: init([files])
78
Initialize the internal data structures. If given, *files* must be a sequence
79
of file names which should be used to augment the default type map. If omitted,
80
the file names to use are taken from :const:`knownfiles`. Each file named in
81
*files* or :const:`knownfiles` takes precedence over those named before it.
82
Calling :func:`init` repeatedly is allowed.
85
.. function:: read_mime_types(filename)
87
Load the type map given in the file *filename*, if it exists. The type map is
88
returned as a dictionary mapping filename extensions, including the leading dot
89
(``'.'``), to strings of the form ``'type/subtype'``. If the file *filename*
90
does not exist or cannot be read, ``None`` is returned.
93
.. function:: add_type(type, ext[, strict])
95
Add a mapping from the mimetype *type* to the extension *ext*. When the
96
extension is already known, the new type will replace the old one. When the type
97
is already known the extension will be added to the list of known extensions.
99
When *strict* is True (the default), the mapping will added to the official MIME
100
types, otherwise to the non-standard ones.
105
Flag indicating whether or not the global data structures have been initialized.
106
This is set to true by :func:`init`.
111
.. index:: single: file; mime.types
113
List of type map file names commonly installed. These files are typically named
114
:file:`mime.types` and are installed in different locations by different
120
Dictionary mapping suffixes to suffixes. This is used to allow recognition of
121
encoded files for which the encoding and the type are indicated by the same
122
extension. For example, the :file:`.tgz` extension is mapped to :file:`.tar.gz`
123
to allow the encoding and type to be recognized separately.
126
.. data:: encodings_map
128
Dictionary mapping filename extensions to encoding types.
133
Dictionary mapping filename extensions to MIME types.
136
.. data:: common_types
138
Dictionary mapping filename extensions to non-standard, but commonly found MIME
141
The :class:`MimeTypes` class may be useful for applications which may want more
142
than one MIME-type database:
145
.. class:: MimeTypes([filenames])
147
This class represents a MIME-types database. By default, it provides access to
148
the same database as the rest of this module. The initial database is a copy of
149
that provided by the module, and may be extended by loading additional
150
:file:`mime.types`\ -style files into the database using the :meth:`read` or
151
:meth:`readfp` methods. The mapping dictionaries may also be cleared before
152
loading additional data if the default data is not desired.
154
The optional *filenames* parameter can be used to cause additional files to be
155
loaded "on top" of the default database.
158
An example usage of the module::
162
>>> mimetypes.knownfiles
163
['/etc/mime.types', '/etc/httpd/mime.types', ... ]
164
>>> mimetypes.suffix_map['.tgz']
166
>>> mimetypes.encodings_map['.gz']
168
>>> mimetypes.types_map['.tgz']
169
'application/x-tar-gz'
172
.. _mimetypes-objects:
177
:class:`MimeTypes` instances provide an interface which is very like that of the
178
:mod:`mimetypes` module.
181
.. attribute:: MimeTypes.suffix_map
183
Dictionary mapping suffixes to suffixes. This is used to allow recognition of
184
encoded files for which the encoding and the type are indicated by the same
185
extension. For example, the :file:`.tgz` extension is mapped to :file:`.tar.gz`
186
to allow the encoding and type to be recognized separately. This is initially a
187
copy of the global ``suffix_map`` defined in the module.
190
.. attribute:: MimeTypes.encodings_map
192
Dictionary mapping filename extensions to encoding types. This is initially a
193
copy of the global ``encodings_map`` defined in the module.
196
.. attribute:: MimeTypes.types_map
198
Dictionary mapping filename extensions to MIME types. This is initially a copy
199
of the global ``types_map`` defined in the module.
202
.. attribute:: MimeTypes.common_types
204
Dictionary mapping filename extensions to non-standard, but commonly found MIME
205
types. This is initially a copy of the global ``common_types`` defined in the
209
.. method:: MimeTypes.guess_extension(type[, strict])
211
Similar to the :func:`guess_extension` function, using the tables stored as part
215
.. method:: MimeTypes.guess_type(url[, strict])
217
Similar to the :func:`guess_type` function, using the tables stored as part of
221
.. method:: MimeTypes.read(path)
223
Load MIME information from a file named *path*. This uses :meth:`readfp` to
227
.. method:: MimeTypes.readfp(file)
229
Load MIME type information from an open file. The file must have the format of
230
the standard :file:`mime.types` files.