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Review the new configparser docs.

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Doc/library/configparser.rst
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......@@ -34,215 +34,211 @@ customized by end users easily.
Support for a creating Unix shell-like mini-languages which can be used
as an alternate format for application configuration files.
Quick Start
-----------
.. highlightlang:: none
Let's take a very basic configuration file that looks like this:
Let's take a very basic configuration file that looks like this::
.. code-block:: ini
[DEFAULT]
ServerAliveInterval = 45
Compression = yes
CompressionLevel = 9
ForwardX11 = yes
[DEFAULT]
ServerAliveInterval = 45
Compression = yes
CompressionLevel = 9
ForwardX11 = yes
[bitbucket.org]
User = hg
[bitbucket.org]
User = hg
[topsecret.server.com]
Port = 50022
ForwardX11 = no
[topsecret.server.com]
Port = 50022
ForwardX11 = no
The supported file structure of INI files is described `in the following section
<#supported-ini-file-structure>`_, fow now all there's to know is that the file
<#supported-ini-file-structure>`_, fow now all there is to know is that 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
:mod:`configparser` classes can read and write such files. Let's start by
creating the above configuration file programatically.
.. highlightlang:: python
.. doctest::
>>> import configparser
>>> config = configparser.RawConfigParser()
>>> 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 just like a dictionary. There are
>>> import configparser
>>> config = configparser.RawConfigParser()
>>> 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 just like a dictionary. There are
a few differences, `outlined later on <#mapping-protocol-access>`_, but the
behaviour is very close to what you'd expect from a dictionary.
behaviour is very close to what you would expect from a dictionary.
Now that we've created and saved a configuration file, let's try reading it
Now that we have created and saved a configuration file, let's try reading it
back and exploring the data it holds.
.. highlightlang:: python
.. doctest::
>>> import configparser
>>> config = configparser.RawConfigParser()
>>> 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 straight forward. The only bit of magic
>>> import configparser
>>> config = configparser.RawConfigParser()
>>> 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 straight forward. The only bit of magic
involves the ``DEFAULT`` section which provides default values for all other
sections [customizable]_. Another thing to note is that keys in sections are
case-insensitive so they're stored in lowercase [customizable]_.
sections [1]_. Another thing to note is that keys in sections are
case-insensitive so they're 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:
storing them internally as strings. This means that if you need other
datatypes, you should convert on your own:
.. highlightlang:: python
.. doctest::
>>> int(topsecret['Port'])
50022
>>> float(topsecret['CompressionLevel'])
9.0
>>> int(topsecret['Port'])
50022
>>> float(topsecret['CompressionLevel'])
9.0
Converting to the boolean type is not that simple, though. Wrapping the return
Converting to the boolean type is not that simple, though. Wrapping the return
value around ``bool()`` would do us no good since ``bool('False')`` is still
``True``. This is why config parsers also provide :meth:`getboolean`. This handy
method is also case insensitive and correctly recognizes boolean values from
``'yes'``/``'no'``, ``'on'``/``'off'`` and ``'1'``/``'0'`` [customizable]_. An
``True``. This is why config parsers also provide :meth:`getboolean`. This
handy method is also case insensitive and correctly recognizes boolean values
from ``'yes'``/``'no'``, ``'on'``/``'off'`` and ``'1'``/``'0'`` [1]_. An
example of getting the boolean value:
.. highlightlang:: python
.. doctest::
>>> topsecret.getboolean('ForwardX11')
False
>>> config['bitbucket.org'].getboolean('ForwardX11')
True
>>> config.getboolean('bitbucket.org', 'Compression')
True
>>> 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
:meth:`getint` and :meth:`getfloat` methods, but these are far less useful
because explicit casting is enough for these types.
Fallback Values
---------------
As with a regular dictionary, you can use a section's :meth:`get` method to
provide fallback values:
.. highlightlang:: python
.. doctest::
>>> topsecret.get('Port')
'50022'
>>> topsecret.get('CompressionLevel')
'9'
>>> topsecret.get('Cipher')
>>> topsecret.get('Cipher', '3des-cbc')
'3des-cbc'
>>> 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
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:
``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:
.. highlightlang:: python
.. doctest::
>>> topsecret.get('CompressionLevel', '3')
'9'
>>> 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
compatibility. When using this method, a fallback value can be provided via the
``fallback`` keyword-only argument:
.. highlightlang:: python
.. doctest::
>>> config.get('bitbucket.org', 'monster',
... fallback='No such things as monsters')
'No such things as monsters'
>>> 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:
.. highlightlang:: python
.. doctest::
>>> 'BatchMode' in topsecret
False
>>> topsecret.getboolean('BatchMode', fallback=True)
True
>>> config['DEFAULT']['BatchMode'] = 'no'
>>> topsecret.getboolean('BatchMode', fallback=True)
False
>>> '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 [customizable]_). By default, section names are case sensitive but keys
are not [customizable]_. Leading und trailing whitespace is removed from keys and from values.
default [1]_). By default, section names are case sensitive but keys are not
[1]_. Leading und trailing whitespace is removed from keys and from 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 [customizable]_). Comments may appear on their own in an
otherwise empty line, or may be entered in lines holding values or section
names. In the latter case, they need to be preceded by a whitespace character
to be recognized as a comment. (For backwards compatibility, by default only
``;`` starts an inline comment, while ``#`` does not [customizable]_.)
and ``;`` by default [1]_). Comments may appear on their own in an otherwise
empty line, or may be entered in lines holding values or section names. In the
latter case, they need to be preceded by a whitespace character to be recognized
as a comment. (For backwards compatibility, by default only ``;`` starts an
inline comment, while ``#`` does not [1]_.)
On top of the core functionality, :class:`SafeConfigParser` supports
interpolation. This means values can contain format strings which refer to
other values in the same section, or values in a special ``DEFAULT`` section
[customizable]_. Additional defaults can be provided on initialization.
[1]_. Additional defaults can be provided on initialization.
.. highlightlang:: none
For example:
For example::
.. code-block:: ini
[Paths]
home_dir: /Users
......@@ -286,20 +282,20 @@ value of ``my_pictures`` and ``%(home_dir)s/lumberjack`` as the value of
``my_dir``. Other features presented in the example are handled in the same
manner by both parsers.
Mapping Protocol Access
-----------------------
.. versionadded:: 3.2
.. highlightlang:: python
Mapping protocol access is a generic name for functionality that enables using
custom objects as if they were dictionaries. In case of :mod:`configparser`,
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
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.
......@@ -307,46 +303,46 @@ parser.
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
[customizable]_. 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``::
* 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"]
"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
* 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``.
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``.
* trying to delete the ``DEFAULTSECT`` throws ``ValueError``
* Trying to delete the ``DEFAULTSECT`` throws ``ValueError``.
* there are two parser-level methods in the legacy API that hide
the dictionary interface and are incompatible:
* There are two parser-level methods in the legacy API that hide the dictionary
interface and are incompatible:
* ``parser.get(section, option, **kwargs)`` - the second argument is **not**
a fallback value
* ``parser.get(section, option, **kwargs)`` - the second argument is **not** a
fallback value
* ``parser.items(section)`` - this returns a list of ``(option, value)``
pairs for a specified ``section``.
* ``parser.items(section)`` - this returns a list of ``(option, value)`` pairs
for a specified ``section``
The mapping protocol is implemented on top of the existing legacy API so that
subclassing the original interface makes the mappings work as expected as well.
One difference is the explicit lack of support for the `__name__` special key.
This is because the existing behaviour of `__name__` is very inconsistent and
supporting it would only lead to problems. Details `here
One difference is the explicit lack of support for the ``__name__`` special key.
This is because the existing behaviour of ``__name__`` is very inconsistent and
supporting it would only lead to problems. Details `here
<http://mail.python.org/pipermail/python-dev/2010-July/102556.html>`_.
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
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.
......@@ -356,7 +352,7 @@ the :meth:`__init__` options:
* *defaults*, default value: ``None``
This option accepts a dictionary of key-value pairs which will be initially
put in the ``DEFAULTSECT``. This makes for an elegant way to support concise
put in the ``DEFAULTSECT``. This makes for an elegant way to support concise
configuration files that don't specify values which are the same as the
documented default.
......@@ -366,68 +362,66 @@ the :meth:`__init__` options:
* *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 will look like. With the default ordered
the written configuration files will look like. With the default ordered
dictionary, every section is stored in the order they were added to the
parser. Same goes for options within sections.
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
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:
operation. When you use a regular dictionary in those operations, the order
of the keys may be random. For example:
.. highlightlang:: python
.. doctest::
>>> parser = configparser.RawConfigParser()
>>> 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']
>>> parser = configparser.RawConfigParser()
>>> 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:
.. highlightlang:: python
.. doctest::
>>> from collections import OrderedDict
>>> parser = configparser.RawConfigParser()
>>> 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']
>>> from collections import OrderedDict
>>> parser = configparser.RawConfigParser()
>>> 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``
......@@ -436,35 +430,34 @@ the :meth:`__init__` options:
*allow_no_value* parameter to the :meth:`__init__` method can be used to
indicate that such values should be accepted:
.. highlightlang:: python
.. doctest::
>>> import configparser
>>> sample_config = """
... [mysqld]
... user = mysql
... pid-file = /var/run/mysqld/mysqld.pid
... skip-external-locking
... old_passwords = 1
... skip-bdb
... skip-innodb # we don't need ACID today
... """
>>> config = configparser.RawConfigParser(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'
>>> import configparser
>>> sample_config = """
... [mysqld]
... user = mysql
... pid-file = /var/run/mysqld/mysqld.pid
... skip-external-locking
... old_passwords = 1
... skip-bdb
... skip-innodb # we don't need ACID today
... """
>>> config = configparser.RawConfigParser(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: ``('=', ':')``
......@@ -480,9 +473,9 @@ the :meth:`__init__` options:
lines, ``';'`` valid also on non-empty lines)
Comment prefixes are substrings that indicate the start of a valid comment
within a config file. The peculiar default value allows for comments starting
within a config file. The peculiar default value allows for comments starting
with ``'#'`` or ``';'`` but only the latter can be used in a non-empty line.
This is obviously dictated by backwards compatibiliy. A more predictable
This is obviously dictated by backwards compatibiliy. A more predictable
approach would be to specify prefixes as ``('#', ';')`` which will allow for
both prefixes to be used in non-empty lines.
......@@ -494,35 +487,34 @@ the :meth:`__init__` options:
If 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`). The default is ``False`` only
because of backwards compatibility reasons. It's recommended to use strict
:meth:`read_string` or :meth:`read_dict`). The default is ``False`` only
because of backwards compatibility reasons. It is recommended to use strict
parsers in new applications.
* *empty_lines_in_values*, default value: ``True``
.. highlightlang:: none
In config parsers, values can be multiline as long as they are indented deeper
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:
In config parsers, values can be multiline as long as they're indented deeper
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's easy for the user to lose track of the file structure. Take for
instance::
.. code-block:: ini
[Section]
key = multiline
value with a gotcha
[Section]
key = multiline
value with a gotcha
this = is still a part of the multiline value of 'key'
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's 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
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``.
.. highlightlang:: python
More advanced customization may be achieved by overriding default values of the
following parser members:
......@@ -531,22 +523,21 @@ following parser members:
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:
following values ``False``: ``'0'``, ``'no'``, ``'false'``, ``'off'``. You
can override this by specifying a custom dictionary of strings and their
boolean outcomes. For example:
.. highlightlang:: python
.. doctest::
>>> custom = configparser.RawConfigParser()
>>> 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
>>> custom = configparser.RawConfigParser()
>>> 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``.
......@@ -554,42 +545,42 @@ following parser members:
* :meth:`RawConfigParser.optionxform`
This is a method that transforms option names on every read or set operation.
By default it converts the name to lowercase. This also means that when
a configuration file gets written, all keys will be lowercase. If you find
that behaviour unsuitable, you can override this method. For example:
By default it converts the name to lowercase. This also means that when a
configuration file gets written, all keys will be lowercase. If you find that
behaviour unsuitable, you can override this method. For example:
.. highlightlang:: python
.. doctest::
>>> config = """
... [Section1]
... Key = Value
...
... [Section2]
... AnotherKey = Value
... """
>>> typical = configparser.RawConfigParser()
>>> 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']
>>> config = """
... [Section1]
... Key = Value
...
... [Section2]
... AnotherKey = Value
... """
>>> typical = configparser.RawConfigParser()
>>> 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']
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.
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::
......@@ -668,7 +659,7 @@ you absolutely have to, a :class:`ConfigParser`::
# -> None
Defaults are available in all three types of ConfigParsers. They are used in
Defaults are available in all three types of ConfigParsers. They are used in
interpolation if an option used is not defined elsewhere. ::
import configparser
......@@ -682,6 +673,7 @@ interpolation if an option used is not defined elsewhere. ::
config.remove_option('Section1', 'baz')
print(config.get('Section1', 'foo')) # -> "Life is hard!"
.. _rawconfigparser-objects:
RawConfigParser Objects
......@@ -720,211 +712,215 @@ RawConfigParser Objects
*empty_lines_in_values* were added.
.. method:: RawConfigParser.defaults()
.. method:: defaults()
Return a dictionary containing the instance-wide defaults.
Return a dictionary containing the instance-wide defaults.
.. method:: RawConfigParser.sections()
.. method:: sections()
Return a list of the sections available; ``DEFAULT`` is not included in the
list.
Return a list of the sections available; ``DEFAULT`` is not included in
the list.
.. method:: RawConfigParser.add_section(section)
.. 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 name
``DEFAULT`` (or any of it's case-insensitive variants) is passed,
:exc:`ValueError` is raised.
Add a section named *section* to the instance. If a section by the given
name already exists, :exc:`DuplicateSectionError` is raised. If the name
``DEFAULT`` (or any of it's case-insensitive variants) is passed,
:exc:`ValueError` is raised.
.. method:: RawConfigParser.has_section(section)
Indicates whether the named section is present in the configuration. The
``DEFAULT`` section is not acknowledged.
.. method:: has_section(section)
Indicates whether the named section is present in the configuration. The
``DEFAULT`` section is not acknowledged.
.. method:: RawConfigParser.options(section)
Returns a list of options available in the specified *section*.
.. method:: options(section)
Return a list of options available in the specified *section*.
.. method:: RawConfigParser.has_option(section, option)
If the given section exists, and contains the given option, return
:const:`True`; otherwise return :const:`False`.
.. method:: has_option(section, option)
If the given section exists, and contains the given option, return
:const:`True`; otherwise return :const:`False`.
.. method:: RawConfigParser.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::
.. method:: read(filenames, encoding=None)
import configparser, os
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::
config = configparser.ConfigParser()
config.read_file(open('defaults.cfg'))
config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')], encoding='cp1250')
import configparser, os
.. versionadded:: 3.2
The *encoding* parameter. Previously, all files were read using the
default encoding for :func:`open`.
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:: RawConfigParser.read_file(f, source=None)
Read and parse configuration data from the file or file-like object in *f*
(only the :meth:`readline` method is used). The file-like object must
operate in text mode, i.e. return strings from :meth:`readline`.
.. method:: read_file(f, source=None)
Optional argument *source* specifies the name of the file being read. It not
given and *f* has a :attr:`name` attribute, that is used for *source*; the
default is ``<???>``.
Read and parse configuration data from the file or file-like object in *f*
(only the :meth:`readline` method is used). The file-like object must
operate in text mode, i.e. return strings from :meth:`readline`.
.. versionadded:: 3.2
Renamed from :meth:`readfp` (with the ``filename`` attribute renamed to
``source`` for consistency with other ``read_*`` methods).
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
Renamed from :meth:`readfp` (with the ``filename`` attribute renamed to
``source`` for consistency with other ``read_*`` methods).
.. method:: RawConfigParser.read_string(string, source='<string>')
Parse configuration data from a given string.
.. method:: read_string(string, source='<string>')
Optional argument *source* specifies a context-specific name of the string
passed. If not given, ``<string>`` is used.
Parse configuration data from a given string.
.. versionadded:: 3.2
Optional argument *source* specifies a context-specific name of the string
passed. If not given, ``<string>`` is used.
.. versionadded:: 3.2
.. method:: RawConfigParser.read_dict(dictionary, source='<dict>')
Load configuration from a dictionary. 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.
.. method:: read_dict(dictionary, source='<dict>')
Optional argument *source* specifies a context-specific name of the
dictionary passed. If not given, ``<dict>`` is used.
Load configuration from a dictionary. 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.
.. versionadded:: 3.2
Optional argument *source* specifies a context-specific name of the
dictionary passed. If not given, ``<dict>`` is used.
.. method:: RawConfigParser.get(section, option, [vars, fallback])
.. versionadded:: 3.2
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.
.. method:: get(section, option, [vars, fallback])
.. versionchanged:: 3.2
Arguments *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).
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.
.. versionchanged:: 3.2
Arguments *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:: RawConfigParser.getint(section, option, [vars, fallback])
A convenience method which coerces the *option* in the specified *section* to
an integer. See :meth:`get` for explanation of *vars* and *fallback*.
.. method:: getint(section, option, [vars, fallback])
A convenience method which coerces the *option* in the specified *section*
to an integer. See :meth:`get` for explanation of *vars* and *fallback*.
.. method:: RawConfigParser.getfloat(section, option, [vars, fallback])
A convenience method which coerces the *option* in the specified *section* to
a floating point number. See :meth:`get` for explanation of *vars* and
*fallback*.
.. method:: getfloat(section, option, [vars, fallback])
A convenience method which coerces the *option* in the specified *section*
to a floating point number. See :meth:`get` for explanation of *vars* and
*fallback*.
.. method:: RawConfigParser.getboolean(section, option, [vars, 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 *vars* and *fallback*.
.. method:: getboolean(section, option, [vars, 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 *vars* and
*fallback*.
.. method:: RawConfigParser.items(section)
Return a list of ``(name, value)`` pairs for each option in the given
*section*.
.. method:: items(section)
Return a list of ``(name, value)`` pairs for each option in the given
*section*.
.. method:: RawConfigParser.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.
.. method:: set(section, option, value)
.. warning::
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.
.. note::
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.
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.
.. method:: RawConfigParser.write(fileobject, space_around_delimiters=True)
.. 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`` (the default), delimiters between
keys and values are surrounded by spaces.
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`` (the default), delimiters between
keys and values are surrounded by spaces.
.. method:: RawConfigParser.remove_option(section, option)
.. 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`.
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:: RawConfigParser.remove_section(section)
.. method:: remove_section(section)
Remove the specified *section* from the configuration. If the section in fact
existed, return ``True``. Otherwise return ``False``.
Remove the specified *section* from the configuration. If the section in
fact existed, return ``True``. Otherwise return ``False``.
.. method:: RawConfigParser.optionxform(option)
.. 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.
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 necessarily need to subclass a ConfigParser to use this method, you
can also re-set it on an instance, to a function that takes a string
argument. Setting it to ``str``, for example, would make option names case
sensitive::
You don't necessarily need to subclass a ConfigParser to use this method,
you can also re-set it on an instance, to a function that takes a string
argument. Setting it to ``str``, for example, would make option names
case sensitive::
cfgparser = ConfigParser()
...
cfgparser.optionxform = str
cfgparser = ConfigParser()
...
cfgparser.optionxform = str
Note that when reading configuration files, whitespace around the
option names are stripped before :meth:`optionxform` is called.
Note that when reading configuration files, whitespace around the option
names are stripped before :meth:`optionxform` is called.
.. method:: RawConfigParser.readfp(fp, filename=None)
.. method:: readfp(fp, filename=None)
.. deprecated:: 3.2
Please use :meth:`read_file` instead.
.. deprecated:: 3.2
Please use :meth:`read_file` instead.
.. _configparser-objects:
......@@ -933,8 +929,8 @@ ConfigParser Objects
--------------------
.. warning::
Whenever you can, consider using :class:`SafeConfigParser` which
adds validation and escaping for the interpolation.
Whenever you can, consider using :class:`SafeConfigParser` which adds
validation and escaping for the interpolation.
The :class:`ConfigParser` class extends some methods of the
:class:`RawConfigParser` interface, adding some optional arguments.
......@@ -966,54 +962,55 @@ The :class:`ConfigParser` class extends some methods of the
*strict* and *empty_lines_in_values* were added.
.. method:: ConfigParser.get(section, option, raw=False, [vars, fallback])
.. method:: get(section, option, raw=False, [vars, 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.
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.
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).
.. 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:: ConfigParser.getint(section, option, raw=False, [vars, fallback])
.. method:: getint(section, option, raw=False, [vars, 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*.
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:: ConfigParser.getfloat(section, option, raw=False, [vars, fallback])
.. method:: getfloat(section, option, raw=False, [vars, 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*.
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:: ConfigParser.getboolean(section, option, raw=False, [vars, fallback])
.. method:: getboolean(section, option, raw=False, [vars, 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*.
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:: ConfigParser.items(section, raw=False, vars=None)
.. method:: items(section, raw=False, vars=None)
Return a list of ``(name, value)`` pairs for each option in the given
*section*. Optional arguments have the same meaning as for the :meth:`get`
method.
Return a list of ``(name, value)`` pairs for each option in the given
*section*. Optional arguments have the same meaning as for the
:meth:`get` method.
.. data:: MAX_INTERPOLATION_DEPTH
......@@ -1021,6 +1018,7 @@ The :class:`ConfigParser` class extends some methods of the
The maximum depth for recursive interpolation for :meth:`get` when the *raw*
parameter is false. This is relevant only for the :class:`ConfigParser` class.
.. _safeconfigparser-objects:
SafeConfigParser Objects
......@@ -1046,14 +1044,14 @@ SafeConfigParser Objects
*empty_lines_in_values* were added.
The :class:`SafeConfigParser` class implements the same extended interface as
:class:`ConfigParser`, with the following addition:
The :class:`SafeConfigParser` class implements the same extended interface as
:class:`ConfigParser`, with the following addition:
.. method:: SafeConfigParser.set(section, option, value)
.. method:: set(section, option, value)
If the given section exists, set the given option to the specified value;
otherwise raise :exc:`NoSectionError`. *value* must be a string; if it is
not, :exc:`TypeError` is raised.
If the given section exists, set the given option to the specified value;
otherwise raise :exc:`NoSectionError`. *value* must be a string; if it is
not, :exc:`TypeError` is raised.
Exceptions
......@@ -1103,25 +1101,26 @@ Exceptions
.. exception:: InterpolationDepthError
Exception raised when string interpolation cannot be completed because the
number of iterations exceeds :const:`MAX_INTERPOLATION_DEPTH`. Subclass of
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 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 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 raised when attempting to parse a file which has no section
headers.
.. exception:: ParsingError
......@@ -1132,6 +1131,9 @@ Exceptions
The ``filename`` attribute and :meth:`__init__` argument were renamed to
``source`` for consistency.
.. [customizable] Config parsers allow for very heavy customization. If you're
interested in changing the behaviour outlined by the footnote
reference, consult the `Customizing Parser Behaviour`_ section.
.. 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.
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