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fix copy-editing level nits

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Fred Drake 2010-11-13 05:24:17 +00:00
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Doc/library/configparser.rst
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@ -18,8 +18,8 @@
single: Windows ini file
This module provides the classes :class:`RawConfigParser` and
:class:`SafeConfigParser`. They implement a basic configuration file parser
language which provides a structure similar to what you would find in Microsoft
:class:`SafeConfigParser`. They implement 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.
@ -55,8 +55,8 @@ Let's take a very basic configuration file that looks like this:
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 is to know is that the file
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.
@ -79,12 +79,12 @@ creating the above configuration file programatically.
... 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 would expect from a dictionary.
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 try reading it
back and exploring the data it holds.
Now that we have created and saved a configuration file, let's read it
back and explore the data it holds.
.. doctest::
@ -119,10 +119,10 @@ back and exploring the data it holds.
>>> config['bitbucket.org']['ForwardX11']
'yes'
As we can see above, the API is pretty straight forward. The only bit of magic
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]_. Another thing to note is that keys in sections are
case-insensitive so they're stored in lowercase [1]_.
sections [1]_. Note also that keys in sections are
case-insensitive and stored in lowercase [1]_.
Supported Datatypes
@ -139,12 +139,12 @@ datatypes, you should convert on your own:
>>> float(topsecret['CompressionLevel'])
9.0
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'`` [1]_. An
example of getting the boolean value:
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::
@ -156,14 +156,15 @@ example of getting the boolean value:
True
Apart from :meth:`getboolean`, config parsers also provide equivalent
:meth:`getint` and :meth:`getfloat` methods, but these are far less useful
because explicit casting is enough for these types.
: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 regular dictionary, you can use a section's :meth:`get` method to
As with a dictionary, you can use a section's :meth:`get` method to
provide fallback values:
.. doctest::
@ -176,11 +177,11 @@ provide fallback values:
>>> 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:
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::
@ -189,8 +190,8 @@ fallback:
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:
compatibility. When using this method, a fallback value can be provided via
the ``fallback`` keyword-only argument:
.. doctest::
@ -218,18 +219,19 @@ 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 und trailing whitespace is removed from keys and from values.
[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 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]_.)
Configuration files may include comments, prefixed by specific
characters (``#`` and ``;`` by default [1]_). Comments may appear on
their own on an otherwise empty line, or may be entered on 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
@ -306,7 +308,7 @@ 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``::
for a section that holds the key ``'a'``, both expressions return ``True``::
"a" in parser["section"]
"A" in parser["section"]
@ -326,14 +328,14 @@ However, there are a few differences that should be taken into account:
* ``parser.get(section, option, **kwargs)`` - the second argument is **not** a
fallback value
* ``parser.items(section)`` - this returns a list of ``(option, value)`` pairs
* ``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 behavior 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>`_.
@ -346,7 +348,7 @@ 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 natural way to change the way a specific config parser works is to use
The most common way to change the way a specific config parser works is to use
the :meth:`__init__` options:
* *defaults*, default value: ``None``
@ -356,13 +358,13 @@ the :meth:`__init__` options:
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 the
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 will look like. With the default ordered
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.
@ -427,7 +429,7 @@ the :meth:`__init__` options:
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 :meth:`__init__` method can be used to
*allow_no_value* parameter to the constructor can be used to
indicate that such values should be accepted:
.. doctest::
@ -463,8 +465,7 @@ the :meth:`__init__` options:
Delimiters are substrings that delimit keys from values within a section. The
first occurence of a delimiting substring on a line is considered a delimiter.
This means values (but not keus) can contain substrings that are in the
*delimiters*.
This means values (but not keys) can contain the delimiters.
See also the *space_around_delimiters* argument to
:meth:`RawConfigParser.write`.
@ -472,7 +473,7 @@ the :meth:`__init__` options:
* *comment_prefixes*, default value: ``_COMPATIBLE`` (``'#'`` valid on empty
lines, ``';'`` valid also on non-empty lines)
Comment prefixes are substrings that indicate the start of a valid comment
Comment prefixes are strings that indicate the start of a valid comment
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
@ -493,12 +494,12 @@ the :meth:`__init__` options:
* *empty_lines_in_values*, default value: ``True``
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 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
@ -516,16 +517,17 @@ the :meth:`__init__` options:
produce two keys, ``key`` and ``this``.
More advanced customization may be achieved by overriding default values of the
following parser members:
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.
* `RawConfigParser.BOOLEAN_STATES`
.. 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:
Boolean outcomes. For example:
.. doctest::
@ -539,15 +541,16 @@ following parser members:
>>> custom['section1'].getboolean('funky')
False
Other typical boolean pairs include ``accept``/``reject`` or
Other typical Boolean pairs include ``accept``/``reject`` or
``enabled``/``disabled``.
* :meth:`RawConfigParser.optionxform`
.. method:: optionxform(option)
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:
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::
@ -624,7 +627,7 @@ An example of reading the configuration file again::
if config.getboolean('Section1', 'bool'):
print(config.get('Section1', 'foo'))
To get interpolation, you will need to use a :class:`SafeConfigParser` or, if
To get interpolation, use :class:`SafeConfigParser` or, if
you absolutely have to, a :class:`ConfigParser`::
import configparser
@ -658,9 +661,8 @@ you absolutely have to, a :class:`ConfigParser`::
print(cfg.get('Section1', 'monster', fallback=None))
# -> None
Defaults are available in all three types of ConfigParsers. They are used in
interpolation if an option used is not defined elsewhere. ::
Default values are available in all three types of ConfigParsers. They are
used in interpolation if an option used is not defined elsewhere. ::
import configparser
@ -681,12 +683,12 @@ RawConfigParser Objects
.. class:: RawConfigParser(defaults=None, dict_type=collections.OrderedDict, allow_no_value=False, delimiters=('=', ':'), comment_prefixes=_COMPATIBLE, strict=False, empty_lines_in_values=True)
The basic configuration object. When *defaults* is given, it is initialized
The basic 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 will be used as the set of substrings that
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 a line, both for the whole
line and inline comments. For backwards compatibility, the default value for
@ -696,7 +698,7 @@ RawConfigParser Objects
When *strict* is ``True`` (default: ``False``), 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``
: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
@ -776,25 +778,26 @@ RawConfigParser Objects
.. method:: 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`.
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. Specifically, it must return strings from
:meth:`readline`.
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 ``<???>``.
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).
Replaces :meth:`readfp`.
.. method:: read_string(string, source='<string>')
Parse configuration data from a given 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.
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
@ -852,7 +855,7 @@ RawConfigParser Objects
.. method:: items(section)
Return a list of ``(name, value)`` pairs for each option in the given
Return a list of *name*, *value* pairs for each option in the given
*section*.
@ -878,7 +881,7 @@ RawConfigParser Objects
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
*space_around_delimiters* is true, delimiters between
keys and values are surrounded by spaces.
@ -904,23 +907,22 @@ RawConfigParser Objects
*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 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 are stripped before :meth:`optionxform` is called.
names is stripped before :meth:`optionxform` is called.
.. method:: readfp(fp, filename=None)
.. deprecated:: 3.2
Please use :meth:`read_file` instead.
Use :meth:`read_file` instead.
.. _configparser-objects:
@ -945,8 +947,8 @@ The :class:`ConfigParser` class extends some methods of the
need interpolation.
The values in *defaults* must be appropriate for the ``%()s`` string
interpolation. Note that *__name__* is an intrinsic default; its value is
the section name, and will override any value provided in *defaults*.
interpolation. Note that ``'__name__'`` is an intrinsic default; its value
is the section name, and will override any value provided in *defaults*.
All option names used in interpolation will be passed through the
:meth:`optionxform` method just like any other option name reference. For
@ -998,8 +1000,8 @@ The :class:`ConfigParser` class extends some methods of the
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
``'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
@ -1008,7 +1010,7 @@ The :class:`ConfigParser` class extends some methods of the
.. method:: items(section, raw=False, vars=None)
Return a list of ``(name, value)`` pairs for each option in the given
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.
@ -1026,10 +1028,10 @@ SafeConfigParser Objects
.. class:: SafeConfigParser(defaults=None, dict_type=collections.OrderedDict, allow_no_value=False, delimiters=('=', ':'), comment_prefixes=_COMPATIBLE, strict=False, empty_lines_in_values=True)
Derived class of :class:`ConfigParser` that implements a sane variant of the
magical interpolation feature. This implementation is more predictable as it
validates the interpolation syntax used within a configuration file. This
class also enables escaping the interpolation character (e.g. a key can have
Derived class of :class:`ConfigParser` that implements a variant of the
magical interpolation feature. This implementation is more predictable as
it validates the interpolation syntax used within a configuration file.
This class also enables escaping the interpolation character (a key can have
``%`` as part of the value by specifying ``%%`` in the file).
Applications that don't require interpolation should use
@ -1044,14 +1046,14 @@ 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:: 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.
otherwise raise :exc:`NoSectionError`. *value* must be a string; if not,
:exc:`TypeError` is raised.
Exceptions
@ -1059,7 +1061,7 @@ Exceptions
.. exception:: Error
Base class for all other configparser exceptions.
Base class for all other :mod:`configparser` exceptions.
.. exception:: NoSectionError