1 :mod:`ConfigParser` --- Configuration file parser
2 =================================================
4 .. module:: ConfigParser
5 :synopsis: Configuration file parser.
7 .. moduleauthor:: Ken Manheimer <klm@zope.com>
8 .. moduleauthor:: Barry Warsaw <bwarsaw@python.org>
9 .. moduleauthor:: Eric S. Raymond <esr@thyrsus.com>
10 .. sectionauthor:: Christopher G. Petrilli <petrilli@amber.org>
14 The :mod:`ConfigParser` module has been renamed to :mod:`configparser` in
15 Python 3.0. The :term:`2to3` tool will automatically adapt imports when
16 converting your sources to 3.0.
20 pair: configuration; file
22 single: Windows ini file
24 This module defines the class :class:`ConfigParser`. The :class:`ConfigParser`
25 class implements a basic configuration file parser language which provides a
26 structure similar to what you would find on Microsoft Windows INI files. You
27 can use this to write Python programs which can be customized by end users
32 This library does *not* interpret or write the value-type prefixes used in
33 the Windows Registry extended version of INI syntax.
35 The configuration file consists of sections, led by a ``[section]`` header and
36 followed by ``name: value`` entries, with continuations in the style of
37 :rfc:`822` (see section 3.1.1, "LONG HEADER FIELDS"); ``name=value`` is also
38 accepted. Note that leading whitespace is removed from values. The optional
39 values can contain format strings which refer to other values in the same
40 section, or values in a special ``DEFAULT`` section. Additional defaults can be
41 provided on initialization and retrieval. Lines beginning with ``'#'`` or
42 ``';'`` are ignored and may be used to provide comments.
47 foodir: %(dir)s/whatever
49 long: this value continues
52 would resolve the ``%(dir)s`` to the value of ``dir`` (``frob`` in this case).
53 All reference expansions are done on demand.
55 Default values can be specified by passing them into the :class:`ConfigParser`
56 constructor as a dictionary. Additional defaults may be passed into the
57 :meth:`get` method which will override all others.
59 Sections are normally stored in a built-in dictionary. An alternative dictionary
60 type can be passed to the :class:`ConfigParser` constructor. For example, if a
61 dictionary type is passed that sorts its keys, the sections will be sorted on
62 write-back, as will be the keys within each section.
65 .. class:: RawConfigParser([defaults[, dict_type]])
67 The basic configuration object. When *defaults* is given, it is initialized
68 into the dictionary of intrinsic defaults. When *dict_type* is given, it will
69 be used to create the dictionary objects for the list of sections, for the
70 options within a section, and for the default values. This class does not
71 support the magical interpolation behavior.
75 .. versionchanged:: 2.6
76 *dict_type* was added.
78 .. versionchanged:: 2.7
79 The default *dict_type* is :class:`collections.OrderedDict`.
82 .. class:: ConfigParser([defaults[, dict_type]])
84 Derived class of :class:`RawConfigParser` that implements the magical
85 interpolation feature and adds optional arguments to the :meth:`get` and
86 :meth:`items` methods. The values in *defaults* must be appropriate for the
87 ``%()s`` string interpolation. Note that *__name__* is an intrinsic default;
88 its value is the section name, and will override any value provided in
91 All option names used in interpolation will be passed through the
92 :meth:`optionxform` method just like any other option name reference. For
93 example, using the default implementation of :meth:`optionxform` (which converts
94 option names to lower case), the values ``foo %(bar)s`` and ``foo %(BAR)s`` are
99 .. versionchanged:: 2.6
100 *dict_type* was added.
102 .. versionchanged:: 2.7
103 The default *dict_type* is :class:`collections.OrderedDict`.
106 .. class:: SafeConfigParser([defaults[, dict_type]])
108 Derived class of :class:`ConfigParser` that implements a more-sane variant of
109 the magical interpolation feature. This implementation is more predictable as
110 well. New applications should prefer this version if they don't need to be
111 compatible with older versions of Python.
113 .. XXX Need to explain what's safer/more predictable about it.
115 .. versionadded:: 2.3
117 .. versionchanged:: 2.6
118 *dict_type* was added.
120 .. versionchanged:: 2.7
121 The default *dict_type* is :class:`collections.OrderedDict`.
124 .. exception:: NoSectionError
126 Exception raised when a specified section is not found.
129 .. exception:: DuplicateSectionError
131 Exception raised if :meth:`add_section` is called with the name of a section
132 that is already present.
135 .. exception:: NoOptionError
137 Exception raised when a specified option is not found in the specified section.
140 .. exception:: InterpolationError
142 Base class for exceptions raised when problems occur performing string
146 .. exception:: InterpolationDepthError
148 Exception raised when string interpolation cannot be completed because the
149 number of iterations exceeds :const:`MAX_INTERPOLATION_DEPTH`. Subclass of
150 :exc:`InterpolationError`.
153 .. exception:: InterpolationMissingOptionError
155 Exception raised when an option referenced from a value does not exist. Subclass
156 of :exc:`InterpolationError`.
158 .. versionadded:: 2.3
161 .. exception:: InterpolationSyntaxError
163 Exception raised when the source text into which substitutions are made does not
164 conform to the required syntax. Subclass of :exc:`InterpolationError`.
166 .. versionadded:: 2.3
169 .. exception:: MissingSectionHeaderError
171 Exception raised when attempting to parse a file which has no section headers.
174 .. exception:: ParsingError
176 Exception raised when errors occur attempting to parse a file.
179 .. data:: MAX_INTERPOLATION_DEPTH
181 The maximum depth for recursive interpolation for :meth:`get` when the *raw*
182 parameter is false. This is relevant only for the :class:`ConfigParser` class.
188 Support for a creating Unix shell-like mini-languages which can be used as an
189 alternate format for application configuration files.
192 .. _rawconfigparser-objects:
194 RawConfigParser Objects
195 -----------------------
197 :class:`RawConfigParser` instances have the following methods:
200 .. method:: RawConfigParser.defaults()
202 Return a dictionary containing the instance-wide defaults.
205 .. method:: RawConfigParser.sections()
207 Return a list of the sections available; ``DEFAULT`` is not included in the
211 .. method:: RawConfigParser.add_section(section)
213 Add a section named *section* to the instance. If a section by the given name
214 already exists, :exc:`DuplicateSectionError` is raised. If the name
215 ``DEFAULT`` (or any of it's case-insensitive variants) is passed,
216 :exc:`ValueError` is raised.
218 .. method:: RawConfigParser.has_section(section)
220 Indicates whether the named section is present in the configuration. The
221 ``DEFAULT`` section is not acknowledged.
224 .. method:: RawConfigParser.options(section)
226 Returns a list of options available in the specified *section*.
229 .. method:: RawConfigParser.has_option(section, option)
231 If the given section exists, and contains the given option, return
232 :const:`True`; otherwise return :const:`False`.
234 .. versionadded:: 1.6
237 .. method:: RawConfigParser.read(filenames)
239 Attempt to read and parse a list of filenames, returning a list of filenames
240 which were successfully parsed. If *filenames* is a string or Unicode string,
241 it is treated as a single filename. If a file named in *filenames* cannot be
242 opened, that file will be ignored. This is designed so that you can specify a
243 list of potential configuration file locations (for example, the current
244 directory, the user's home directory, and some system-wide directory), and all
245 existing configuration files in the list will be read. If none of the named
246 files exist, the :class:`ConfigParser` instance will contain an empty dataset.
247 An application which requires initial values to be loaded from a file should
248 load the required file or files using :meth:`readfp` before calling :meth:`read`
249 for any optional files::
251 import ConfigParser, os
253 config = ConfigParser.ConfigParser()
254 config.readfp(open('defaults.cfg'))
255 config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')])
257 .. versionchanged:: 2.4
258 Returns list of successfully parsed filenames.
261 .. method:: RawConfigParser.readfp(fp[, filename])
263 Read and parse configuration data from the file or file-like object in *fp*
264 (only the :meth:`readline` method is used). If *filename* is omitted and *fp*
265 has a :attr:`name` attribute, that is used for *filename*; the default is
269 .. method:: RawConfigParser.get(section, option)
271 Get an *option* value for the named *section*.
274 .. method:: RawConfigParser.getint(section, option)
276 A convenience method which coerces the *option* in the specified *section* to an
280 .. method:: RawConfigParser.getfloat(section, option)
282 A convenience method which coerces the *option* in the specified *section* to a
283 floating point number.
286 .. method:: RawConfigParser.getboolean(section, option)
288 A convenience method which coerces the *option* in the specified *section* to a
289 Boolean value. Note that the accepted values for the option are ``"1"``,
290 ``"yes"``, ``"true"``, and ``"on"``, which cause this method to return ``True``,
291 and ``"0"``, ``"no"``, ``"false"``, and ``"off"``, which cause it to return
292 ``False``. These string values are checked in a case-insensitive manner. Any
293 other value will cause it to raise :exc:`ValueError`.
296 .. method:: RawConfigParser.items(section)
298 Return a list of ``(name, value)`` pairs for each option in the given *section*.
301 .. method:: RawConfigParser.set(section, option, value)
303 If the given section exists, set the given option to the specified value;
304 otherwise raise :exc:`NoSectionError`. While it is possible to use
305 :class:`RawConfigParser` (or :class:`ConfigParser` with *raw* parameters set to
306 true) for *internal* storage of non-string values, full functionality (including
307 interpolation and output to files) can only be achieved using string values.
309 .. versionadded:: 1.6
312 .. method:: RawConfigParser.write(fileobject)
314 Write a representation of the configuration to the specified file object. This
315 representation can be parsed by a future :meth:`read` call.
317 .. versionadded:: 1.6
320 .. method:: RawConfigParser.remove_option(section, option)
322 Remove the specified *option* from the specified *section*. If the section does
323 not exist, raise :exc:`NoSectionError`. If the option existed to be removed,
324 return :const:`True`; otherwise return :const:`False`.
326 .. versionadded:: 1.6
329 .. method:: RawConfigParser.remove_section(section)
331 Remove the specified *section* from the configuration. If the section in fact
332 existed, return ``True``. Otherwise return ``False``.
335 .. method:: RawConfigParser.optionxform(option)
337 Transforms the option name *option* as found in an input file or as passed in by
338 client code to the form that should be used in the internal structures. The
339 default implementation returns a lower-case version of *option*; subclasses may
340 override this or client code can set an attribute of this name on instances to
341 affect this behavior. Setting this to :func:`str`, for example, would make
342 option names case sensitive.
345 .. _configparser-objects:
350 The :class:`ConfigParser` class extends some methods of the
351 :class:`RawConfigParser` interface, adding some optional arguments.
354 .. method:: ConfigParser.get(section, option[, raw[, vars]])
356 Get an *option* value for the named *section*. All the ``'%'`` interpolations
357 are expanded in the return values, based on the defaults passed into the
358 constructor, as well as the options *vars* provided, unless the *raw* argument
362 .. method:: ConfigParser.items(section[, raw[, vars]])
364 Return a list of ``(name, value)`` pairs for each option in the given *section*.
365 Optional arguments have the same meaning as for the :meth:`get` method.
367 .. versionadded:: 2.3
370 .. _safeconfigparser-objects:
372 SafeConfigParser Objects
373 ------------------------
375 The :class:`SafeConfigParser` class implements the same extended interface as
376 :class:`ConfigParser`, with the following addition:
379 .. method:: SafeConfigParser.set(section, option, value)
381 If the given section exists, set the given option to the specified value;
382 otherwise raise :exc:`NoSectionError`. *value* must be a string (:class:`str`
383 or :class:`unicode`); if not, :exc:`TypeError` is raised.
385 .. versionadded:: 2.4
391 An example of writing to a configuration file::
395 config = ConfigParser.RawConfigParser()
397 # When adding sections or items, add them in the reverse order of
398 # how you want them to be displayed in the actual file.
399 # In addition, please note that using RawConfigParser's and the raw
400 # mode of ConfigParser's respective set functions, you can assign
401 # non-string values to keys internally, but will receive an error
402 # when attempting to write to a file or when you get it in non-raw
403 # mode. SafeConfigParser does not allow such assignments to take place.
404 config.add_section('Section1')
405 config.set('Section1', 'int', '15')
406 config.set('Section1', 'bool', 'true')
407 config.set('Section1', 'float', '3.1415')
408 config.set('Section1', 'baz', 'fun')
409 config.set('Section1', 'bar', 'Python')
410 config.set('Section1', 'foo', '%(bar)s is %(baz)s!')
412 # Writing our configuration file to 'example.cfg'
413 with open('example.cfg', 'wb') as configfile:
414 config.write(configfile)
416 An example of reading the configuration file again::
420 config = ConfigParser.RawConfigParser()
421 config.read('example.cfg')
423 # getfloat() raises an exception if the value is not a float
424 # getint() and getboolean() also do this for their respective types
425 float = config.getfloat('Section1', 'float')
426 int = config.getint('Section1', 'int')
429 # Notice that the next output does not interpolate '%(bar)s' or '%(baz)s'.
430 # This is because we are using a RawConfigParser().
431 if config.getboolean('Section1', 'bool'):
432 print config.get('Section1', 'foo')
434 To get interpolation, you will need to use a :class:`ConfigParser` or
435 :class:`SafeConfigParser`::
439 config = ConfigParser.ConfigParser()
440 config.read('example.cfg')
442 # Set the third, optional argument of get to 1 if you wish to use raw mode.
443 print config.get('Section1', 'foo', 0) # -> "Python is fun!"
444 print config.get('Section1', 'foo', 1) # -> "%(bar)s is %(baz)s!"
446 # The optional fourth argument is a dict with members that will take
447 # precedence in interpolation.
448 print config.get('Section1', 'foo', 0, {'bar': 'Documentation',
451 Defaults are available in all three types of ConfigParsers. They are used in
452 interpolation if an option used is not defined elsewhere. ::
456 # New instance with 'bar' and 'baz' defaulting to 'Life' and 'hard' each
457 config = ConfigParser.SafeConfigParser({'bar': 'Life', 'baz': 'hard'})
458 config.read('example.cfg')
460 print config.get('Section1', 'foo') # -> "Python is fun!"
461 config.remove_option('Section1', 'bar')
462 config.remove_option('Section1', 'baz')
463 print config.get('Section1', 'foo') # -> "Life is hard!"
465 The function ``opt_move`` below can be used to move options between sections::
467 def opt_move(config, section1, section2, option):
469 config.set(section2, option, config.get(section1, option, 1))
470 except ConfigParser.NoSectionError:
471 # Create non-existent section
472 config.add_section(section2)
473 opt_move(config, section1, section2, option)
475 config.remove_option(section1, option)