| :mod:`configparser` --- Configuration file parser |
| ================================================= |
| |
| .. module:: configparser |
| :synopsis: Configuration file parser. |
| |
| .. moduleauthor:: Ken Manheimer <klm@zope.com> |
| .. moduleauthor:: Barry Warsaw <bwarsaw@python.org> |
| .. moduleauthor:: Eric S. Raymond <esr@thyrsus.com> |
| .. moduleauthor:: Łukasz Langa <lukasz@langa.pl> |
| .. sectionauthor:: Christopher G. Petrilli <petrilli@amber.org> |
| .. sectionauthor:: Łukasz Langa <lukasz@langa.pl> |
| |
| .. 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 a 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. |
| |
| |
| Quick Start |
| ----------- |
| |
| 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 programatically. |
| |
| .. 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:: |
| |
| >>> import configparser |
| >>> 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']: 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]_. |
| |
| |
| Supported Datatypes |
| ------------------- |
| |
| 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 |
| |
| Extracting Boolean values is not that simple, though. Passing the value |
| to ``bool()`` would do no good since ``bool('False')`` is still |
| ``True``. This is why config parsers also provide :meth:`getboolean`. |
| This method is case-insensitive and recognizes Boolean values from |
| ``'yes'``/``'no'``, ``'on'``/``'off'`` 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:`getboolean`, config parsers also provide equivalent |
| :meth:`getint` and :meth:`getfloat` methods, but these are far less |
| useful since conversion using :func:`int` and :func:`float` is |
| sufficient for these types. |
| |
| |
| Fallback Values |
| --------------- |
| |
| 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:`getint`, |
| :meth:`getfloat` and :meth:`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 |
| |
| |
| Supported INI File Structure |
| ---------------------------- |
| |
| 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] |
| # like this |
| ; or this |
| |
| # By default only in an empty line. |
| # Inline comments can be harmful because they prevent users |
| # from using the delimiting characters as parts of values. |
| # That being said, this can be customized. |
| |
| [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? |
| |
| |
| Interpolation of values |
| ----------------------- |
| |
| On top of the core functionality, :class:`ConfigParser` supports |
| interpolation. This means values can be preprocessed before returning them |
| from ``get()`` calls. |
| |
| .. 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``. |
| |
| .. 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} |
| |
| Mapping Protocol Access |
| ----------------------- |
| |
| .. 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 ``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 overriden in the section, deleting causes |
| the default value to be visible again. Trying to delete a default value |
| causes a ``KeyError``. |
| |
| * ``DEFAULTSECT`` cannot be removed from the parser: |
| |
| * trying to delete it raises ``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. |
| |
| |
| Customizing Parser Behaviour |
| ---------------------------- |
| |
| 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 may be random. 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() |
| ['section3', 'section2', 'section1'] |
| >>> [option for option in parser['section3']] |
| ['baz', 'foo', 'bar'] |
| |
| In these operations you need to use an ordered dictionary as well: |
| |
| .. doctest:: |
| |
| >>> from collections import OrderedDict |
| >>> parser = configparser.ConfigParser() |
| >>> parser.read_dict( |
| ... OrderedDict(( |
| ... ('s1', |
| ... OrderedDict(( |
| ... ('1', '2'), |
| ... ('3', '4'), |
| ... ('5', '6'), |
| ... )) |
| ... ), |
| ... ('s2', |
| ... OrderedDict(( |
| ... ('a', 'b'), |
| ... ('c', 'd'), |
| ... ('e', 'f'), |
| ... )) |
| ... ), |
| ... )) |
| ... ) |
| >>> parser.sections() |
| ['s1', 's2'] |
| >>> [option for option in parser['s1']] |
| ['1', '3', '5'] |
| >>> [option for option in parser['s2'].values()] |
| ['b', 'd', 'f'] |
| |
| * *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']) |
| |
| #!/usr/bin/env python |
| # -*- coding: utf-8 -*- |
| >>> print(parser['hashes']['extensions']) |
| |
| 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``. |
| |
| |
| 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 overriden by subclasses or by attribute assignment. |
| |
| .. attribute:: BOOLEAN_STATES |
| |
| By default when using :meth:`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:: 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:: 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:: |
| |
| >>> config = """ |
| ... [Section 1] |
| ... option = value |
| ... |
| ... [ Section 2 ] |
| ... another = val |
| ... """ |
| >>> typical = ConfigParser() |
| >>> typical.read_string(config) |
| >>> typical.sections() |
| ['Section 1', ' Section 2 '] |
| >>> custom = 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*. |
| |
| |
| Legacy API Examples |
| ------------------- |
| |
| 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() |
| |
| # Please note that using RawConfigParser's set functions, you can assign |
| # non-string values to keys internally, but will receive an error when |
| # attempting to write to a file or when you get it in non-raw mode. Setting |
| # values using the mapping protocol or ConfigParser's set() does not allow |
| # such assignments to take place. |
| 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!') |
| |
| # Writing our configuration file to 'example.cfg' |
| 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') |
| |
| # getfloat() raises an exception if the value is not a float |
| # getint() and getboolean() also do this for their respective types |
| a_float = config.getfloat('Section1', 'a_float') |
| an_int = config.getint('Section1', 'an_int') |
| print(a_float + an_int) |
| |
| # Notice that the next output does not interpolate '%(bar)s' or '%(baz)s'. |
| # This is because we are using a RawConfigParser(). |
| 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') |
| |
| # Set the optional *raw* argument of get() to True if you wish to disable |
| # interpolation in a single get operation. |
| print(cfg.get('Section1', 'foo', raw=False)) # -> "Python is fun!" |
| print(cfg.get('Section1', 'foo', raw=True)) # -> "%(bar)s is %(baz)s!" |
| |
| # The optional *vars* argument is a dict with members that will take |
| # precedence in interpolation. |
| print(cfg.get('Section1', 'foo', vars={'bar': 'Documentation', |
| 'baz': 'evil'})) |
| |
| # The optional *fallback* argument can be used to provide a fallback value |
| 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." |
| |
| # A bare print(cfg.get('Section1', 'monster')) would raise NoOptionError |
| # but we can also use: |
| |
| 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 |
| |
| # New instance with 'bar' and 'baz' defaulting to 'Life' and 'hard' each |
| 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: |
| |
| 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()) |
| |
| 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. |
| |
| .. 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. |
| |
| |
| .. 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 a list of filenames, returning a list of |
| filenames which were successfully parsed. If *filenames* is a string, 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 a list 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 list 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`. |
| |
| |
| .. 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. |
| |
| .. versionchanged:: 3.2 |
| Items present in *vars* no longer appear in the result. The previous |
| behaviour mixed actual parser options with variables provided for |
| interpolation. |
| |
| .. 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 *f* instead of calling ``f.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(f): |
| line = f.readline() |
| while line: |
| yield line |
| line = f.readline() |
| |
| Instead of ``parser.readfp(f)`` use |
| ``parser.read_file(readline_generator(f))``. |
| |
| |
| .. 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: |
| |
| 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` with interpolation disabled |
| by default and unsafe ``add_section`` and ``set`` methods. |
| |
| .. 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. |
| |
| |
| Exceptions |
| ---------- |
| |
| .. 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. |