kbe/src/lib/python/Doc/library/configparser.rst
configparser --- Configuration file parser.. module:: configparser :synopsis: Configuration file parser.
.. moduleauthor:: Ken Manheimer [email protected] .. moduleauthor:: Barry Warsaw [email protected] .. moduleauthor:: Eric S. Raymond [email protected] .. moduleauthor:: Łukasz Langa [email protected] .. sectionauthor:: Christopher G. Petrilli [email protected] .. sectionauthor:: Łukasz Langa [email protected]
Source code: :source:Lib/configparser.py
.. index:: pair: .ini; file pair: configuration; file single: ini file single: Windows ini file
This module provides the :class:ConfigParser class which implements a basic
configuration language which provides a structure similar to what's found in
Microsoft Windows INI files. You can use this to write Python programs which
can be customized by end users easily.
.. note::
This library does not interpret or write the value-type prefixes used in the Windows Registry extended version of INI syntax.
.. seealso::
Module :mod:shlex
Support for creating Unix shell-like mini-languages which can be used as
an alternate format for application configuration files.
Module :mod:json
The json module implements a subset of JavaScript syntax which can also
be used for this purpose.
.. testsetup::
import configparser
Let's take a very basic configuration file that looks like this:
.. code-block:: ini
[DEFAULT] ServerAliveInterval = 45 Compression = yes CompressionLevel = 9 ForwardX11 = yes
[bitbucket.org] User = hg
[topsecret.server.com] Port = 50022 ForwardX11 = no
The structure of INI files is described in the following section <#supported-ini-file-structure>_. Essentially, the file
consists of sections, each of which contains keys with values.
:mod:configparser classes can read and write such files. Let's start by
creating the above configuration file programmatically.
.. doctest::
import configparser config = configparser.ConfigParser() config['DEFAULT'] = {'ServerAliveInterval': '45', ... 'Compression': 'yes', ... 'CompressionLevel': '9'} config['bitbucket.org'] = {} config['bitbucket.org']['User'] = 'hg' config['topsecret.server.com'] = {} topsecret = config['topsecret.server.com'] topsecret['Port'] = '50022' # mutates the parser topsecret['ForwardX11'] = 'no' # same here config['DEFAULT']['ForwardX11'] = 'yes' with open('example.ini', 'w') as configfile: ... config.write(configfile) ...
As you can see, we can treat a config parser much like a dictionary.
There are differences, outlined later <#mapping-protocol-access>_, but
the behavior is very close to what you would expect from a dictionary.
Now that we have created and saved a configuration file, let's read it back and explore the data it holds.
.. doctest::
config = configparser.ConfigParser() config.sections() [] config.read('example.ini') ['example.ini'] config.sections() ['bitbucket.org', 'topsecret.server.com'] 'bitbucket.org' in config True 'bytebong.com' in config False config['bitbucket.org']['User'] 'hg' config['DEFAULT']['Compression'] 'yes' topsecret = config['topsecret.server.com'] topsecret['ForwardX11'] 'no' topsecret['Port'] '50022' for key in config['bitbucket.org']: # doctest: +SKIP ... print(key) user compressionlevel serveraliveinterval compression forwardx11 config['bitbucket.org']['ForwardX11'] 'yes'
As we can see above, the API is pretty straightforward. The only bit of magic
involves the DEFAULT section which provides default values for all other
sections [1]. Note also that keys in sections are
case-insensitive and stored in lowercase [1].
Config parsers do not guess datatypes of values in configuration files, always storing them internally as strings. This means that if you need other datatypes, you should convert on your own:
.. doctest::
int(topsecret['Port']) 50022 float(topsecret['CompressionLevel']) 9.0
Since this task is so common, config parsers provide a range of handy getter
methods to handle integers, floats and booleans. The last one is the most
interesting because simply passing the value to bool() would do no good
since bool('False') is still True. This is why config parsers also
provide :meth:~ConfigParser.getboolean. This method is case-insensitive and
recognizes Boolean values from 'yes'/'no', 'on'/'off',
'true'/'false' and '1'/'0' [1]_. For example:
.. doctest::
topsecret.getboolean('ForwardX11') False config['bitbucket.org'].getboolean('ForwardX11') True config.getboolean('bitbucket.org', 'Compression') True
Apart from :meth:~ConfigParser.getboolean, config parsers also
provide equivalent :meth:~ConfigParser.getint and
:meth:~ConfigParser.getfloat methods. You can register your own
converters and customize the provided ones. [1]_
As with a dictionary, you can use a section's :meth:get method to
provide fallback values:
.. doctest::
topsecret.get('Port') '50022' topsecret.get('CompressionLevel') '9' topsecret.get('Cipher') topsecret.get('Cipher', '3des-cbc') '3des-cbc'
Please note that default values have precedence over fallback values.
For instance, in our example the 'CompressionLevel' key was
specified only in the 'DEFAULT' section. If we try to get it from
the section 'topsecret.server.com', we will always get the default,
even if we specify a fallback:
.. doctest::
topsecret.get('CompressionLevel', '3') '9'
One more thing to be aware of is that the parser-level :meth:get method
provides a custom, more complex interface, maintained for backwards
compatibility. When using this method, a fallback value can be provided via
the fallback keyword-only argument:
.. doctest::
config.get('bitbucket.org', 'monster', ... fallback='No such things as monsters') 'No such things as monsters'
The same fallback argument can be used with the
:meth:~ConfigParser.getint, :meth:~ConfigParser.getfloat and
:meth:~ConfigParser.getboolean methods, for example:
.. doctest::
'BatchMode' in topsecret False topsecret.getboolean('BatchMode', fallback=True) True config['DEFAULT']['BatchMode'] = 'no' topsecret.getboolean('BatchMode', fallback=True) False
A configuration file consists of sections, each led by a [section] header,
followed by key/value entries separated by a specific string (= or : by
default [1]). By default, section names are case sensitive but keys are not
[1]. Leading and trailing whitespace is removed from keys and values.
Values can be omitted, in which case the key/value delimiter may also be left
out. Values can also span multiple lines, as long as they are indented deeper
than the first line of the value. Depending on the parser's mode, blank lines
may be treated as parts of multiline values or ignored.
Configuration files may include comments, prefixed by specific
characters (# and ; by default [1]). Comments may appear on
their own on an otherwise empty line, possibly indented. [1]
For example:
.. code-block:: ini
[Simple Values] key=value spaces in keys=allowed spaces in values=allowed as well spaces around the delimiter = obviously you can also use : to delimit keys from values
[All Values Are Strings] values like this: 1000000 or this: 3.14159265359 are they treated as numbers? : no integers, floats and booleans are held as: strings can use the API to get converted values directly: true
[Multiline Values] chorus: I'm a lumberjack, and I'm okay I sleep all night and I work all day
[No Values] key_without_value empty string value here =
[You can use comments]
; or this
[Sections Can Be Indented]
can_values_be_as_well = True
does_that_mean_anything_special = False
purpose = formatting for readability
multiline_values = are
handled just fine as
long as they are indented
deeper than the first line
of a value
# Did I mention we can indent comments, too?
On top of the core functionality, :class:ConfigParser supports
interpolation. This means values can be preprocessed before returning them
from get() calls.
.. index:: single: % (percent); interpolation in configuration files
.. class:: BasicInterpolation()
The default implementation used by :class:ConfigParser. It enables
values to contain format strings which refer to other values in the same
section, or values in the special default section [1]_. Additional default
values can be provided on initialization.
For example:
.. code-block:: ini
[Paths]
home_dir: /Users
my_dir: %(home_dir)s/lumberjack
my_pictures: %(my_dir)s/Pictures
In the example above, :class:ConfigParser with interpolation set to
BasicInterpolation() would resolve %(home_dir)s to the value of
home_dir (/Users in this case). %(my_dir)s in effect would
resolve to /Users/lumberjack. All interpolations are done on demand so
keys used in the chain of references do not have to be specified in any
specific order in the configuration file.
With interpolation set to None, the parser would simply return
%(my_dir)s/Pictures as the value of my_pictures and
%(home_dir)s/lumberjack as the value of my_dir.
.. index:: single: $ (dollar); interpolation in configuration files
.. class:: ExtendedInterpolation()
An alternative handler for interpolation which implements a more advanced
syntax, used for instance in zc.buildout. Extended interpolation is
using ${section:option} to denote a value from a foreign section.
Interpolation can span multiple levels. For convenience, if the
section: part is omitted, interpolation defaults to the current section
(and possibly the default values from the special section).
For example, the configuration specified above with basic interpolation, would look like this with extended interpolation:
.. code-block:: ini
[Paths]
home_dir: /Users
my_dir: ${home_dir}/lumberjack
my_pictures: ${my_dir}/Pictures
Values from other sections can be fetched as well:
.. code-block:: ini
[Common]
home_dir: /Users
library_dir: /Library
system_dir: /System
macports_dir: /opt/local
[Frameworks]
Python: 3.2
path: ${Common:system_dir}/Library/Frameworks/
[Arthur]
nickname: Two Sheds
last_name: Jackson
my_dir: ${Common:home_dir}/twosheds
my_pictures: ${my_dir}/Pictures
python_dir: ${Frameworks:path}/Python/Versions/${Frameworks:Python}
.. versionadded:: 3.2
Mapping protocol access is a generic name for functionality that enables using
custom objects as if they were dictionaries. In case of :mod:configparser,
the mapping interface implementation is using the
parser['section']['option'] notation.
parser['section'] in particular returns a proxy for the section's data in
the parser. This means that the values are not copied but they are taken from
the original parser on demand. What's even more important is that when values
are changed on a section proxy, they are actually mutated in the original
parser.
:mod:configparser objects behave as close to actual dictionaries as possible.
The mapping interface is complete and adheres to the
:class:~collections.abc.MutableMapping ABC.
However, there are a few differences that should be taken into account:
By default, all keys in sections are accessible in a case-insensitive manner
[1]_. E.g. for option in parser["section"] yields only optionxform'ed
option key names. This means lowercased keys by default. At the same time,
for a section that holds the key 'a', both expressions return True::
"a" in parser["section"] "A" in parser["section"]
All sections include DEFAULTSECT values as well which means that
.clear() on a section may not leave the section visibly empty. This is
because default values cannot be deleted from the section (because technically
they are not there). If they are overridden in the section, deleting causes
the default value to be visible again. Trying to delete a default value
causes a :exc:KeyError.
DEFAULTSECT cannot be removed from the parser:
trying to delete it raises :exc:ValueError,
parser.clear() leaves it intact,
parser.popitem() never returns it.
parser.get(section, option, **kwargs) - the second argument is not
a fallback value. Note however that the section-level get() methods are
compatible both with the mapping protocol and the classic configparser API.
parser.items() is compatible with the mapping protocol (returns a list of
section_name, section_proxy pairs including the DEFAULTSECT). However,
this method can also be invoked with arguments: parser.items(section, raw, vars). The latter call returns a list of option, value pairs for
a specified section, with all interpolations expanded (unless
raw=True is provided).
The mapping protocol is implemented on top of the existing legacy API so that subclasses overriding the original interface still should have mappings working as expected.
There are nearly as many INI format variants as there are applications using it.
:mod:configparser goes a long way to provide support for the largest sensible
set of INI styles available. The default functionality is mainly dictated by
historical background and it's very likely that you will want to customize some
of the features.
The most common way to change the way a specific config parser works is to use
the :meth:__init__ options:
defaults, default value: None
This option accepts a dictionary of key-value pairs which will be initially
put in the DEFAULT section. This makes for an elegant way to support
concise configuration files that don't specify values which are the same as
the documented default.
Hint: if you want to specify default values for a specific section, use
:meth:read_dict before you read the actual file.
dict_type, default value: :class:collections.OrderedDict
This option has a major impact on how the mapping protocol will behave and how the written configuration files look. With the default ordered dictionary, every section is stored in the order they were added to the parser. Same goes for options within sections.
An alternative dictionary type can be used for example to sort sections and options on write-back. You can also use a regular dictionary for performance reasons.
Please note: there are ways to add a set of key-value pairs in a single operation. When you use a regular dictionary in those operations, the order of the keys will be ordered because dict preserves order from Python 3.7. For example:
.. doctest::
parser = configparser.ConfigParser() parser.read_dict({'section1': {'key1': 'value1', ... 'key2': 'value2', ... 'key3': 'value3'}, ... 'section2': {'keyA': 'valueA', ... 'keyB': 'valueB', ... 'keyC': 'valueC'}, ... 'section3': {'foo': 'x', ... 'bar': 'y', ... 'baz': 'z'} ... }) parser.sections() ['section1', 'section2', 'section3'] [option for option in parser['section3']] ['foo', 'bar', 'baz']
allow_no_value, default value: False
Some configuration files are known to include settings without values, but
which otherwise conform to the syntax supported by :mod:configparser. The
allow_no_value parameter to the constructor can be used to
indicate that such values should be accepted:
.. doctest::
import configparser
sample_config = """ ... [mysqld] ... user = mysql ... pid-file = /var/run/mysqld/mysqld.pid ... skip-external-locking ... old_passwords = 1 ... skip-bdb ... # we don't need ACID today ... skip-innodb ... """ config = configparser.ConfigParser(allow_no_value=True) config.read_string(sample_config)
Settings with values are treated as before:
config["mysqld"]["user"] 'mysql'
Settings without values provide None:
config["mysqld"]["skip-bdb"]
Settings which aren't specified still raise an error:
config["mysqld"]["does-not-exist"] Traceback (most recent call last): ... KeyError: 'does-not-exist'
delimiters, default value: ('=', ':')
Delimiters are substrings that delimit keys from values within a section. The first occurrence of a delimiting substring on a line is considered a delimiter. This means values (but not keys) can contain the delimiters.
See also the space_around_delimiters argument to
:meth:ConfigParser.write.
comment_prefixes, default value: ('#', ';')
inline_comment_prefixes, default value: None
Comment prefixes are strings that indicate the start of a valid comment within
a config file. comment_prefixes are used only on otherwise empty lines
(optionally indented) whereas inline_comment_prefixes can be used after
every valid value (e.g. section names, options and empty lines as well). By
default inline comments are disabled and '#' and ';' are used as
prefixes for whole line comments.
.. versionchanged:: 3.2
In previous versions of :mod:configparser behaviour matched
comment_prefixes=('#',';') and inline_comment_prefixes=(';',).
Please note that config parsers don't support escaping of comment prefixes so using inline_comment_prefixes may prevent users from specifying option values with characters used as comment prefixes. When in doubt, avoid setting inline_comment_prefixes. In any circumstances, the only way of storing comment prefix characters at the beginning of a line in multiline values is to interpolate the prefix, for example::
from configparser import ConfigParser, ExtendedInterpolation parser = ConfigParser(interpolation=ExtendedInterpolation())
the default BasicInterpolation could be used as well
parser.read_string(""" ... [DEFAULT] ... hash = # ... ... [hashes] ... shebang = ... ${hash}!/usr/bin/env python ... ${hash} -- coding: utf-8 -- ... ... extensions = ... enabled_extension ... another_extension ... #disabled_by_comment ... yet_another_extension ... ... interpolation not necessary = if # is not at line start ... even in multiline values = line #1 ... line #2 ... line #3 ... """) print(parser['hashes']['shebang'])
<BLANKLINE>
#!/usr/bin/env python
print(parser['hashes']['extensions'])
<BLANKLINE>
enabled_extension another_extension yet_another_extension
print(parser['hashes']['interpolation not necessary']) if # is not at line start print(parser['hashes']['even in multiline values']) line #1 line #2 line #3
strict, default value: True
When set to True, the parser will not allow for any section or option
duplicates while reading from a single source (using :meth:read_file,
:meth:read_string or :meth:read_dict). It is recommended to use strict
parsers in new applications.
.. versionchanged:: 3.2
In previous versions of :mod:configparser behaviour matched
strict=False.
empty_lines_in_values, default value: True
In config parsers, values can span multiple lines as long as they are indented more than the key that holds them. By default parsers also let empty lines to be parts of values. At the same time, keys can be arbitrarily indented themselves to improve readability. In consequence, when configuration files get big and complex, it is easy for the user to lose track of the file structure. Take for instance:
.. code-block:: ini
[Section] key = multiline value with a gotcha
this = is still a part of the multiline value of 'key'
This can be especially problematic for the user to see if she's using a
proportional font to edit the file. That is why when your application does
not need values with empty lines, you should consider disallowing them. This
will make empty lines split keys every time. In the example above, it would
produce two keys, key and this.
default_section, default value: configparser.DEFAULTSECT (that is:
"DEFAULT")
The convention of allowing a special section of default values for other
sections or interpolation purposes is a powerful concept of this library,
letting users create complex declarative configurations. This section is
normally called "DEFAULT" but this can be customized to point to any
other valid section name. Some typical values include: "general" or
"common". The name provided is used for recognizing default sections
when reading from any source and is used when writing configuration back to
a file. Its current value can be retrieved using the
parser_instance.default_section attribute and may be modified at runtime
(i.e. to convert files from one format to another).
interpolation, default value: configparser.BasicInterpolation
Interpolation behaviour may be customized by providing a custom handler
through the interpolation argument. None can be used to turn off
interpolation completely, ExtendedInterpolation() provides a more
advanced variant inspired by zc.buildout. More on the subject in the
dedicated documentation section <#interpolation-of-values>_.
:class:RawConfigParser has a default value of None.
converters, default value: not set
Config parsers provide option value getters that perform type conversion. By
default :meth:~ConfigParser.getint, :meth:~ConfigParser.getfloat, and
:meth:~ConfigParser.getboolean are implemented. Should other getters be
desirable, users may define them in a subclass or pass a dictionary where each
key is a name of the converter and each value is a callable implementing said
conversion. For instance, passing {'decimal': decimal.Decimal} would add
:meth:getdecimal on both the parser object and all section proxies. In
other words, it will be possible to write both
parser_instance.getdecimal('section', 'key', fallback=0) and
parser_instance['section'].getdecimal('key', 0).
If the converter needs to access the state of the parser, it can be
implemented as a method on a config parser subclass. If the name of this
method starts with get, it will be available on all section proxies, in
the dict-compatible form (see the getdecimal() example above).
More advanced customization may be achieved by overriding default values of these parser attributes. The defaults are defined on the classes, so they may be overridden by subclasses or by attribute assignment.
.. attribute:: ConfigParser.BOOLEAN_STATES
By default when using :meth:~ConfigParser.getboolean, config parsers
consider the following values True: '1', 'yes', 'true',
'on' and the following values False: '0', 'no', 'false',
'off'. You can override this by specifying a custom dictionary of strings
and their Boolean outcomes. For example:
.. doctest::
>>> custom = configparser.ConfigParser()
>>> custom['section1'] = {'funky': 'nope'}
>>> custom['section1'].getboolean('funky')
Traceback (most recent call last):
...
ValueError: Not a boolean: nope
>>> custom.BOOLEAN_STATES = {'sure': True, 'nope': False}
>>> custom['section1'].getboolean('funky')
False
Other typical Boolean pairs include accept/reject or
enabled/disabled.
.. method:: ConfigParser.optionxform(option)
This method transforms option names on every read, get, or set operation. The default converts the name to lowercase. This also means that when a configuration file gets written, all keys will be lowercase. Override this method if that's unsuitable. For example:
.. doctest::
>>> config = """
... [Section1]
... Key = Value
...
... [Section2]
... AnotherKey = Value
... """
>>> typical = configparser.ConfigParser()
>>> typical.read_string(config)
>>> list(typical['Section1'].keys())
['key']
>>> list(typical['Section2'].keys())
['anotherkey']
>>> custom = configparser.RawConfigParser()
>>> custom.optionxform = lambda option: option
>>> custom.read_string(config)
>>> list(custom['Section1'].keys())
['Key']
>>> list(custom['Section2'].keys())
['AnotherKey']
.. attribute:: ConfigParser.SECTCRE
A compiled regular expression used to parse section headers. The default
matches [section] to the name "section". Whitespace is considered
part of the section name, thus [ larch ] will be read as a section of
name " larch ". Override this attribute if that's unsuitable. For
example:
.. doctest::
>>> import re
>>> config = """
... [Section 1]
... option = value
...
... [ Section 2 ]
... another = val
... """
>>> typical = configparser.ConfigParser()
>>> typical.read_string(config)
>>> typical.sections()
['Section 1', ' Section 2 ']
>>> custom = configparser.ConfigParser()
>>> custom.SECTCRE = re.compile(r"\[ *(?P<header>[^]]+?) *\]")
>>> custom.read_string(config)
>>> custom.sections()
['Section 1', 'Section 2']
.. note::
While ConfigParser objects also use an ``OPTCRE`` attribute for recognizing
option lines, it's not recommended to override it because that would
interfere with constructor options *allow_no_value* and *delimiters*.
Mainly because of backwards compatibility concerns, :mod:configparser
provides also a legacy API with explicit get/set methods. While there
are valid use cases for the methods outlined below, mapping protocol access is
preferred for new projects. The legacy API is at times more advanced,
low-level and downright counterintuitive.
An example of writing to a configuration file::
import configparser
config = configparser.RawConfigParser()
config.add_section('Section1') config.set('Section1', 'an_int', '15') config.set('Section1', 'a_bool', 'true') config.set('Section1', 'a_float', '3.1415') config.set('Section1', 'baz', 'fun') config.set('Section1', 'bar', 'Python') config.set('Section1', 'foo', '%(bar)s is %(baz)s!')
with open('example.cfg', 'w') as configfile: config.write(configfile)
An example of reading the configuration file again::
import configparser
config = configparser.RawConfigParser() config.read('example.cfg')
a_float = config.getfloat('Section1', 'a_float') an_int = config.getint('Section1', 'an_int') print(a_float + an_int)
if config.getboolean('Section1', 'a_bool'): print(config.get('Section1', 'foo'))
To get interpolation, use :class:ConfigParser::
import configparser
cfg = configparser.ConfigParser() cfg.read('example.cfg')
print(cfg.get('Section1', 'foo', raw=False)) # -> "Python is fun!" print(cfg.get('Section1', 'foo', raw=True)) # -> "%(bar)s is %(baz)s!"
print(cfg.get('Section1', 'foo', vars={'bar': 'Documentation', 'baz': 'evil'}))
print(cfg.get('Section1', 'foo')) # -> "Python is fun!"
print(cfg.get('Section1', 'foo', fallback='Monty is not.')) # -> "Python is fun!"
print(cfg.get('Section1', 'monster', fallback='No such things as monsters.')) # -> "No such things as monsters."
print(cfg.get('Section1', 'monster', fallback=None)) # -> None
Default values are available in both types of ConfigParsers. They are used in interpolation if an option used is not defined elsewhere. ::
import configparser
config = configparser.ConfigParser({'bar': 'Life', 'baz': 'hard'}) config.read('example.cfg')
print(config.get('Section1', 'foo')) # -> "Python is fun!" config.remove_option('Section1', 'bar') config.remove_option('Section1', 'baz') print(config.get('Section1', 'foo')) # -> "Life is hard!"
.. _configparser-objects:
.. class:: ConfigParser(defaults=None, dict_type=collections.OrderedDict, allow_no_value=False, delimiters=('=', ':'), comment_prefixes=('#', ';'), inline_comment_prefixes=None, strict=True, empty_lines_in_values=True, default_section=configparser.DEFAULTSECT, interpolation=BasicInterpolation(), converters={})
The main configuration parser. When defaults is given, it is initialized into the dictionary of intrinsic defaults. When dict_type is given, it will be used to create the dictionary objects for the list of sections, for the options within a section, and for the default values.
When delimiters is given, it is used as the set of substrings that divide keys from values. When comment_prefixes is given, it will be used as the set of substrings that prefix comments in otherwise empty lines. Comments can be indented. When inline_comment_prefixes is given, it will be used as the set of substrings that prefix comments in non-empty lines.
When strict is True (the default), the parser won't allow for
any section or option duplicates while reading from a single source (file,
string or dictionary), raising :exc:DuplicateSectionError or
:exc:DuplicateOptionError. When empty_lines_in_values is False
(default: True), each empty line marks the end of an option. Otherwise,
internal empty lines of a multiline option are kept as part of the value.
When allow_no_value is True (default: False), options without
values are accepted; the value held for these is None and they are
serialized without the trailing delimiter.
When default_section is given, it specifies the name for the special
section holding default values for other sections and interpolation purposes
(normally named "DEFAULT"). This value can be retrieved and changed on
runtime using the default_section instance attribute.
Interpolation behaviour may be customized by providing a custom handler
through the interpolation argument. None can be used to turn off
interpolation completely, ExtendedInterpolation() provides a more
advanced variant inspired by zc.buildout. More on the subject in the
dedicated documentation section <#interpolation-of-values>_.
All option names used in interpolation will be passed through the
:meth:optionxform method just like any other option name reference. For
example, using the default implementation of :meth:optionxform (which
converts option names to lower case), the values foo %(bar)s and foo %(BAR)s are equivalent.
When converters is given, it should be a dictionary where each key
represents the name of a type converter and each value is a callable
implementing the conversion from string to the desired datatype. Every
converter gets its own corresponding :meth:get*() method on the parser
object and section proxies.
.. versionchanged:: 3.1
The default dict_type is :class:collections.OrderedDict.
.. versionchanged:: 3.2 allow_no_value, delimiters, comment_prefixes, strict, empty_lines_in_values, default_section and interpolation were added.
.. versionchanged:: 3.5 The converters argument was added.
.. versionchanged:: 3.7
The defaults argument is read with :meth:read_dict(),
providing consistent behavior across the parser: non-string
keys and values are implicitly converted to strings.
.. method:: defaults()
Return a dictionary containing the instance-wide defaults.
.. method:: sections()
Return a list of the sections available; the *default section* is not
included in the list.
.. method:: add_section(section)
Add a section named *section* to the instance. If a section by the given
name already exists, :exc:`DuplicateSectionError` is raised. If the
*default section* name is passed, :exc:`ValueError` is raised. The name
of the section must be a string; if not, :exc:`TypeError` is raised.
.. versionchanged:: 3.2
Non-string section names raise :exc:`TypeError`.
.. method:: has_section(section)
Indicates whether the named *section* is present in the configuration.
The *default section* is not acknowledged.
.. method:: options(section)
Return a list of options available in the specified *section*.
.. method:: has_option(section, option)
If the given *section* exists, and contains the given *option*, return
:const:`True`; otherwise return :const:`False`. If the specified
*section* is :const:`None` or an empty string, DEFAULT is assumed.
.. method:: read(filenames, encoding=None)
Attempt to read and parse an iterable of filenames, returning a list of
filenames which were successfully parsed.
If *filenames* is a string, a :class:`bytes` object or a
:term:`path-like object`, it is treated as
a single filename. If a file named in *filenames* cannot be opened, that
file will be ignored. This is designed so that you can specify an
iterable of potential configuration file locations (for example, the
current directory, the user's home directory, and some system-wide
directory), and all existing configuration files in the iterable will be
read.
If none of the named files exist, the :class:`ConfigParser`
instance will contain an empty dataset. An application which requires
initial values to be loaded from a file should load the required file or
files using :meth:`read_file` before calling :meth:`read` for any
optional files::
import configparser, os
config = configparser.ConfigParser()
config.read_file(open('defaults.cfg'))
config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')],
encoding='cp1250')
.. versionadded:: 3.2
The *encoding* parameter. Previously, all files were read using the
default encoding for :func:`open`.
.. versionadded:: 3.6.1
The *filenames* parameter accepts a :term:`path-like object`.
.. versionadded:: 3.7
The *filenames* parameter accepts a :class:`bytes` object.
.. method:: read_file(f, source=None)
Read and parse configuration data from *f* which must be an iterable
yielding Unicode strings (for example files opened in text mode).
Optional argument *source* specifies the name of the file being read. If
not given and *f* has a :attr:`name` attribute, that is used for
*source*; the default is ``'<???>'``.
.. versionadded:: 3.2
Replaces :meth:`readfp`.
.. method:: read_string(string, source='<string>')
Parse configuration data from a string.
Optional argument *source* specifies a context-specific name of the
string passed. If not given, ``'<string>'`` is used. This should
commonly be a filesystem path or a URL.
.. versionadded:: 3.2
.. method:: read_dict(dictionary, source='<dict>')
Load configuration from any object that provides a dict-like ``items()``
method. Keys are section names, values are dictionaries with keys and
values that should be present in the section. If the used dictionary
type preserves order, sections and their keys will be added in order.
Values are automatically converted to strings.
Optional argument *source* specifies a context-specific name of the
dictionary passed. If not given, ``<dict>`` is used.
This method can be used to copy state between parsers.
.. versionadded:: 3.2
.. method:: get(section, option, *, raw=False, vars=None[, fallback])
Get an *option* value for the named *section*. If *vars* is provided, it
must be a dictionary. The *option* is looked up in *vars* (if provided),
*section*, and in *DEFAULTSECT* in that order. If the key is not found
and *fallback* is provided, it is used as a fallback value. ``None`` can
be provided as a *fallback* value.
All the ``'%'`` interpolations are expanded in the return values, unless
the *raw* argument is true. Values for interpolation keys are looked up
in the same manner as the option.
.. versionchanged:: 3.2
Arguments *raw*, *vars* and *fallback* are keyword only to protect
users from trying to use the third argument as the *fallback* fallback
(especially when using the mapping protocol).
.. method:: getint(section, option, *, raw=False, vars=None[, fallback])
A convenience method which coerces the *option* in the specified *section*
to an integer. See :meth:`get` for explanation of *raw*, *vars* and
*fallback*.
.. method:: getfloat(section, option, *, raw=False, vars=None[, fallback])
A convenience method which coerces the *option* in the specified *section*
to a floating point number. See :meth:`get` for explanation of *raw*,
*vars* and *fallback*.
.. method:: getboolean(section, option, *, raw=False, vars=None[, fallback])
A convenience method which coerces the *option* in the specified *section*
to a Boolean value. Note that the accepted values for the option are
``'1'``, ``'yes'``, ``'true'``, and ``'on'``, which cause this method to
return ``True``, and ``'0'``, ``'no'``, ``'false'``, and ``'off'``, which
cause it to return ``False``. These string values are checked in a
case-insensitive manner. Any other value will cause it to raise
:exc:`ValueError`. See :meth:`get` for explanation of *raw*, *vars* and
*fallback*.
.. method:: items(raw=False, vars=None) items(section, raw=False, vars=None)
When *section* is not given, return a list of *section_name*,
*section_proxy* pairs, including DEFAULTSECT.
Otherwise, return a list of *name*, *value* pairs for the options in the
given *section*. Optional arguments have the same meaning as for the
:meth:`get` method.
.. method:: set(section, option, value)
If the given section exists, set the given option to the specified value;
otherwise raise :exc:`NoSectionError`. *option* and *value* must be
strings; if not, :exc:`TypeError` is raised.
.. method:: write(fileobject, space_around_delimiters=True)
Write a representation of the configuration to the specified :term:`file
object`, which must be opened in text mode (accepting strings). This
representation can be parsed by a future :meth:`read` call. If
*space_around_delimiters* is true, delimiters between
keys and values are surrounded by spaces.
.. method:: remove_option(section, option)
Remove the specified *option* from the specified *section*. If the
section does not exist, raise :exc:`NoSectionError`. If the option
existed to be removed, return :const:`True`; otherwise return
:const:`False`.
.. method:: remove_section(section)
Remove the specified *section* from the configuration. If the section in
fact existed, return ``True``. Otherwise return ``False``.
.. method:: optionxform(option)
Transforms the option name *option* as found in an input file or as passed
in by client code to the form that should be used in the internal
structures. The default implementation returns a lower-case version of
*option*; subclasses may override this or client code can set an attribute
of this name on instances to affect this behavior.
You don't need to subclass the parser to use this method, you can also
set it on an instance, to a function that takes a string argument and
returns a string. Setting it to ``str``, for example, would make option
names case sensitive::
cfgparser = ConfigParser()
cfgparser.optionxform = str
Note that when reading configuration files, whitespace around the option
names is stripped before :meth:`optionxform` is called.
.. method:: readfp(fp, filename=None)
.. deprecated:: 3.2
Use :meth:`read_file` instead.
.. versionchanged:: 3.2
:meth:`readfp` now iterates on *fp* instead of calling ``fp.readline()``.
For existing code calling :meth:`readfp` with arguments which don't
support iteration, the following generator may be used as a wrapper
around the file-like object::
def readline_generator(fp):
line = fp.readline()
while line:
yield line
line = fp.readline()
Instead of ``parser.readfp(fp)`` use
``parser.read_file(readline_generator(fp))``.
.. data:: MAX_INTERPOLATION_DEPTH
The maximum depth for recursive interpolation for :meth:get when the raw
parameter is false. This is relevant only when the default interpolation
is used.
.. _rawconfigparser-objects:
.. class:: RawConfigParser(defaults=None, dict_type=collections.OrderedDict,
allow_no_value=False, *, delimiters=('=', ':'),
comment_prefixes=('#', ';'),
inline_comment_prefixes=None, strict=True,
empty_lines_in_values=True,
default_section=configparser.DEFAULTSECT[,
interpolation])
Legacy variant of the :class:ConfigParser. It has interpolation
disabled by default and allows for non-string section names, option
names, and values via its unsafe add_section and set methods,
as well as the legacy defaults= keyword argument handling.
.. note::
Consider using :class:ConfigParser instead which checks types of
the values to be stored internally. If you don't want interpolation, you
can use ConfigParser(interpolation=None).
.. method:: add_section(section)
Add a section named *section* to the instance. If a section by the given
name already exists, :exc:`DuplicateSectionError` is raised. If the
*default section* name is passed, :exc:`ValueError` is raised.
Type of *section* is not checked which lets users create non-string named
sections. This behaviour is unsupported and may cause internal errors.
.. method:: set(section, option, value)
If the given section exists, set the given option to the specified value;
otherwise raise :exc:`NoSectionError`. While it is possible to use
:class:`RawConfigParser` (or :class:`ConfigParser` with *raw* parameters
set to true) for *internal* storage of non-string values, full
functionality (including interpolation and output to files) can only be
achieved using string values.
This method lets users assign non-string values to keys internally. This
behaviour is unsupported and will cause errors when attempting to write
to a file or get it in non-raw mode. **Use the mapping protocol API**
which does not allow such assignments to take place.
.. exception:: Error
Base class for all other :mod:configparser exceptions.
.. exception:: NoSectionError
Exception raised when a specified section is not found.
.. exception:: DuplicateSectionError
Exception raised if :meth:add_section is called with the name of a section
that is already present or in strict parsers when a section if found more
than once in a single input file, string or dictionary.
.. versionadded:: 3.2
Optional source and lineno attributes and arguments to
:meth:__init__ were added.
.. exception:: DuplicateOptionError
Exception raised by strict parsers if a single option appears twice during reading from a single file, string or dictionary. This catches misspellings and case sensitivity-related errors, e.g. a dictionary may have two keys representing the same case-insensitive configuration key.
.. exception:: NoOptionError
Exception raised when a specified option is not found in the specified section.
.. exception:: InterpolationError
Base class for exceptions raised when problems occur performing string interpolation.
.. exception:: InterpolationDepthError
Exception raised when string interpolation cannot be completed because the
number of iterations exceeds :const:MAX_INTERPOLATION_DEPTH. Subclass of
:exc:InterpolationError.
.. exception:: InterpolationMissingOptionError
Exception raised when an option referenced from a value does not exist.
Subclass of :exc:InterpolationError.
.. exception:: InterpolationSyntaxError
Exception raised when the source text into which substitutions are made does
not conform to the required syntax. Subclass of :exc:InterpolationError.
.. exception:: MissingSectionHeaderError
Exception raised when attempting to parse a file which has no section headers.
.. exception:: ParsingError
Exception raised when errors occur attempting to parse a file.
.. versionchanged:: 3.2
The filename attribute and :meth:__init__ argument were renamed to
source for consistency.
.. rubric:: Footnotes
.. [1] Config parsers allow for heavy customization. If you are interested in
changing the behaviour outlined by the footnote reference, consult the
Customizing Parser Behaviour_ section.