configparser —- Configuration file parser

Source code:Lib/configparser.py

This module provides the ConfigParser class which implements a basicconfiguration language which provides a structure similar to what's found inMicrosoft Windows INI files. You can use this to write Python programs whichcan be customized by end users easily.

注解

This library does not interpret or write the value-type prefixes used inthe Windows Registry extended version of INI syntax.

参见

• 模块 shlex

• Support for creating Unix shell-like mini-languages which can be used asan alternate format for application configuration files.

• 模块 json

• The json module implements a subset of JavaScript syntax which can alsobe used for this purpose.

Quick Start

Let's take a very basic configuration file that looks like this:

[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. Essentially, the fileconsists of sections, each of which contains keys with values.configparser classes can read and write such files. Let's start bycreating the above configuration file programmatically.

>>> 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, butthe 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 itback and explore the data it holds.

>>> 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 magicinvolves the DEFAULT section which provides default values for all othersections 1. Note also that keys in sections arecase-insensitive and stored in lowercase 1.

Supported Datatypes

Config parsers do not guess datatypes of values in configuration files, alwaysstoring them internally as strings. This means that if you need otherdatatypes, you should convert on your own:

>>> int(topsecret['Port'])
50022
>>> float(topsecret['CompressionLevel'])
9.0

Since this task is so common, config parsers provide a range of handy gettermethods to handle integers, floats and booleans. The last one is the mostinteresting because simply passing the value to bool() would do no goodsince bool('False') is still True. This is why config parsers alsoprovide getboolean(). This method is case-insensitive andrecognizes Boolean values from 'yes'/'no', 'on'/'off','true'/'false' and '1'/'0' 1. For example:

>>> topsecret.getboolean('ForwardX11')
False
>>> config['bitbucket.org'].getboolean('ForwardX11')
True
>>> config.getboolean('bitbucket.org', 'Compression')
True

Apart from getboolean(), config parsers alsoprovide equivalent getint() andgetfloat() methods. You can register your ownconverters and customize the provided ones. 1

Fallback Values

As with a dictionary, you can use a section's get() method toprovide fallback values:

>>> 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 wasspecified only in the 'DEFAULT' section. If we try to get it fromthe section 'topsecret.server.com', we will always get the default,even if we specify a fallback:

>>> topsecret.get('CompressionLevel', '3')
'9'

One more thing to be aware of is that the parser-level get() methodprovides a custom, more complex interface, maintained for backwardscompatibility. When using this method, a fallback value can be provided viathe fallback keyword-only argument:

>>> config.get('bitbucket.org', 'monster',
...            fallback='No such things as monsters')
'No such things as monsters'

The same fallback argument can be used with thegetint(), getfloat() andgetboolean() methods, for example:

>>> '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 : bydefault 1). By default, section names are case sensitive but keys are not1. Leading and trailing whitespace is removed from keys and values.Values can be omitted, in which case the key/value delimiter may also be leftout. Values can also span multiple lines, as long as they are indented deeperthan the first line of the value. Depending on the parser's mode, blank linesmay be treated as parts of multiline values or ignored.

Configuration files may include comments, prefixed by specificcharacters (# and ; by default 1). Comments may appear ontheir own on an otherwise empty line, possibly indented. 1

例如:

[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, ConfigParser supportsinterpolation. This means values can be preprocessed before returning themfrom get() calls.

• class configparser.BasicInterpolation
• The default implementation used by ConfigParser. It enablesvalues to contain format strings which refer to other values in the samesection, or values in the special default section 1. Additional defaultvalues can be provided on initialization.

例如:

[Paths]
home_dir: /Users
my_dir: %(home_dir)s/lumberjack
my_pictures: %(my_dir)s/Pictures
 
[Escape]
gain: 80%%  # use a %% to escape the % sign (% is the only character that needs to be escaped)

In the example above, ConfigParser with interpolation set toBasicInterpolation() would resolve %(home_dir)s to the value ofhome_dir (/Users in this case). %(my_dir)s in effect wouldresolve to /Users/lumberjack. All interpolations are done on demand sokeys used in the chain of references do not have to be specified in anyspecific 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 configparser.ExtendedInterpolation
• An alternative handler for interpolation which implements a more advancedsyntax, used for instance in zc.buildout. Extended interpolation isusing ${section:option} to denote a value from a foreign section.Interpolation can span multiple levels. For convenience, if thesection: 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:

[Paths]
home_dir: /Users
my_dir: ${home_dir}/lumberjack
my_pictures: ${my_dir}/Pictures
 
[Escape]
cost: $$80  # use a $$ to escape the $ sign ($ is the only character that needs to be escaped)

Values from other sections can be fetched as well:

[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

3.2 新版功能.

Mapping protocol access is a generic name for functionality that enables usingcustom objects as if they were dictionaries. In case of configparser,the mapping interface implementation is using theparser['section']['option'] notation.

parser['section'] in particular returns a proxy for the section's data inthe parser. This means that the values are not copied but they are taken fromthe original parser on demand. What's even more important is that when valuesare changed on a section proxy, they are actually mutated in the originalparser.

configparser objects behave as close to actual dictionaries as possible.The mapping interface is complete and adheres to theMutableMapping 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 manner1. E.g. for option in parser["section"] yields only optionxform'edoption 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 isbecause default values cannot be deleted from the section (because technicallythey are not there). If they are overridden in the section, deleting causesthe default value to be visible again. Trying to delete a default valuecauses 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 arecompatible both with the mapping protocol and the classic configparser API.

• parser.items() is compatible with the mapping protocol (returns a list ofsection_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 fora specified section, with all interpolations expanded (unlessraw=True is provided).

The mapping protocol is implemented on top of the existing legacy API so thatsubclasses overriding the original interface still should have mappings workingas expected.

Customizing Parser Behaviour

There are nearly as many INI format variants as there are applications using it.configparser goes a long way to provide support for the largest sensibleset of INI styles available. The default functionality is mainly dictated byhistorical background and it's very likely that you will want to customize someof the features.

The most common way to change the way a specific config parser works is to usethe init() options:

• defaults, default value: None

This option accepts a dictionary of key-value pairs which will be initiallyput in the DEFAULT section. This makes for an elegant way to supportconcise configuration files that don't specify values which are the same asthe documented default.

Hint: if you want to specify default values for a specific section, useread_dict() before you read the actual file.

• dict_type, default value: collections.OrderedDict

This option has a major impact on how the mapping protocol will behave and howthe written configuration files look. With the default ordereddictionary, every section is stored in the order they were added to theparser. Same goes for options within sections.

An alternative dictionary type can be used for example to sort sections andoptions on write-back. You can also use a regular dictionary for performancereasons.

Please note: there are ways to add a set of key-value pairs in a singleoperation. When you use a regular dictionary in those operations, the orderof the keys will be ordered because dict preserves order from Python 3.7.For example:

>>> parser = configparser.ConfigParser()
>>> parser.read_dict({'section1': {'key1': 'value1',
...                                'key2': 'value2',
...                                'key3': 'value3'},
...                   'section2': {'keyA': 'valueA',
...                                'keyB': 'valueB',
...                                'keyC': 'valueC'},
...                   'section3': {'foo': 'x',
...                                'bar': 'y',
...                                'baz': 'z'}
... })
>>> parser.sections()
['section1', 'section2', 'section3']
>>> [option for option in parser['section3']]
['foo', 'bar', 'baz']

• allow_no_value, default value: False

Some configuration files are known to include settings without values, butwhich otherwise conform to the syntax supported by configparser. Theallow_no_value parameter to the constructor can be used toindicate that such values should be accepted:

>>> 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 considereda delimiter. This means values (but not keys) can contain the delimiters.

See also the space_around_delimiters argument toConfigParser.write().

• comment_prefixes, default value: ('#', ';')

• inline_comment_prefixes, default value: None

Comment prefixes are strings that indicate the start of a valid comment withina config file. comment_prefixes are used only on otherwise empty lines(optionally indented) whereas inline_comment_prefixes can be used afterevery valid value (e.g. section names, options and empty lines as well). Bydefault inline comments are disabled and '#' and ';' are used asprefixes for whole line comments.

在 3.2 版更改: In previous versions of configparser behaviour matchedcomment_prefixes=('#',';') and inline_comment_prefixes=(';',).

Please note that config parsers don't support escaping of comment prefixes sousing inline_comment_prefixes may prevent users from specifying optionvalues with characters used as comment prefixes. When in doubt, avoidsetting inline_comment_prefixes. In any circumstances, the only way ofstoring comment prefix characters at the beginning of a line in multilinevalues 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 optionduplicates while reading from a single source (using read_file(),read_string() or read_dict()). It is recommended to use strictparsers in new applications.

在 3.2 版更改: In previous versions of configparser behaviour matchedstrict=False.

• empty_lines_in_values, default value: True

In config parsers, values can span multiple lines as long as they areindented more than the key that holds them. By default parsers also letempty lines to be parts of values. At the same time, keys can be arbitrarilyindented themselves to improve readability. In consequence, whenconfiguration files get big and complex, it is easy for the user to losetrack of the file structure. Take for instance:

[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 aproportional font to edit the file. That is why when your application doesnot need values with empty lines, you should consider disallowing them. Thiswill make empty lines split keys every time. In the example above, it wouldproduce 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 othersections or interpolation purposes is a powerful concept of this library,letting users create complex declarative configurations. This section isnormally called "DEFAULT" but this can be customized to point to anyother valid section name. Some typical values include: "general" or"common". The name provided is used for recognizing default sectionswhen reading from any source and is used when writing configuration back toa file. Its current value can be retrieved using theparser_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 handlerthrough the interpolation argument. None can be used to turn offinterpolation completely, ExtendedInterpolation() provides a moreadvanced variant inspired by zc.buildout. More on the subject in thededicated documentation section.RawConfigParser has a default value of None.

• converters, default value: not set

Config parsers provide option value getters that perform type conversion. Bydefault getint(), getfloat(), andgetboolean() are implemented. Should other getters bedesirable, users may define them in a subclass or pass a dictionary where eachkey is a name of the converter and each value is a callable implementing saidconversion. For instance, passing {'decimal': decimal.Decimal} would addgetdecimal() on both the parser object and all section proxies. Inother words, it will be possible to write bothparser_instance.getdecimal('section', 'key', fallback=0) andparser_instance['section'].getdecimal('key', 0).

If the converter needs to access the state of the parser, it can beimplemented as a method on a config parser subclass. If the name of thismethod starts with get, it will be available on all section proxies, inthe dict-compatible form (see the getdecimal() example above).

More advanced customization may be achieved by overriding default values ofthese parser attributes. The defaults are defined on the classes, so they maybe overridden by subclasses or by attribute assignment.

• ConfigParser.BOOLEAN_STATES
• By default when using getboolean(), config parsersconsider 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 stringsand their Boolean outcomes. For example:

>>> 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 orenabled/disabled.

• ConfigParser.optionxform(option)
• This method transforms option names on every read, get, or setoperation. The default converts the name to lowercase. This alsomeans that when a configuration file gets written, all keys will belowercase. Override this method if that's unsuitable.For example:

>>> 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']

注解

The optionxform function transforms option names to a canonical form.This should be an idempotent function: if the name is already incanonical form, it should be returned unchanged.

• ConfigParser.SECTCRE
• A compiled regular expression used to parse section headers. The defaultmatches [section] to the name "section". Whitespace is consideredpart of the section name, thus [ larch ] will be read as a section ofname " larch ". Override this attribute if that's unsuitable. Forexample:

>>> import re
>>> config = """
... [Section 1]
... option = value
...
... [  Section 2  ]
... another = val
... """
>>> typical = configparser.ConfigParser()
>>> typical.read_string(config)
>>> typical.sections()
['Section 1', '  Section 2  ']
>>> custom = configparser.ConfigParser()
>>> custom.SECTCRE = re.compile(r"\[ *(?P<header>[^]]+?) *\]")
>>> custom.read_string(config)
>>> custom.sections()
['Section 1', 'Section 2']

注解

While ConfigParser objects also use an OPTCRE attribute for recognizingoption lines, it's not recommended to override it because that wouldinterfere with constructor options allow_no_value and delimiters.

Legacy API Examples

Mainly because of backwards compatibility concerns, configparserprovides also a legacy API with explicit get/set methods. While thereare valid use cases for the methods outlined below, mapping protocol access ispreferred 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 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 ininterpolation 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

• class configparser.ConfigParser(defaults=None, dict_type=collections.OrderedDict, allow_no_value=False, delimiters=('=', ':'), comment_prefixes=('#', ';'), inline_comment_prefixes=None, strict=True, empty_lines_in_values=True, default_section=configparser.DEFAULTSECT, interpolation=BasicInterpolation(), converters={})
• The main configuration parser. When defaults is given, it is initializedinto the dictionary of intrinsic defaults. When dict_type is given, itwill be used to create the dictionary objects for the list of sections, forthe options within a section, and for the default values.

When delimiters is given, it is used as the set of substrings thatdivide keys from values. When comment_prefixes is given, it will be usedas the set of substrings that prefix comments in otherwise empty lines.Comments can be indented. When inline_comment_prefixes is given, it willbe used as the set of substrings that prefix comments in non-empty lines.

When strict is True (the default), the parser won't allow forany section or option duplicates while reading from a single source (file,string or dictionary), raising DuplicateSectionError orDuplicateOptionError. 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 withoutvalues are accepted; the value held for these is None and they areserialized without the trailing delimiter.

When default_section is given, it specifies the name for the specialsection holding default values for other sections and interpolation purposes(normally named "DEFAULT"). This value can be retrieved and changed onruntime using the default_section instance attribute.

Interpolation behaviour may be customized by providing a custom handlerthrough the interpolation argument. None can be used to turn offinterpolation completely, ExtendedInterpolation() provides a moreadvanced variant inspired by zc.buildout. More on the subject in thededicated documentation section.

All option names used in interpolation will be passed through theoptionxform() method just like any other option name reference. Forexample, using the default implementation of optionxform() (whichconverts option names to lower case), the values foo %(bar)s and foo%(BAR)s are equivalent.

When converters is given, it should be a dictionary where each keyrepresents the name of a type converter and each value is a callableimplementing the conversion from string to the desired datatype. Everyconverter gets its own corresponding get*() method on the parserobject and section proxies.

在 3.1 版更改: The default dict_type is collections.OrderedDict.

在 3.2 版更改: allow_no_value, delimiters, comment_prefixes, strict,empty_lines_in_values, default_section and interpolation wereadded.

在 3.5 版更改: The converters argument was added.

在 3.7 版更改: The defaults argument is read with read_dict(),providing consistent behavior across the parser: non-stringkeys and values are implicitly converted to strings.

• defaults()

• Return a dictionary containing the instance-wide defaults.

• sections()

• Return a list of the sections available; the default section is notincluded in the list.

• addsection(_section)

• Add a section named section to the instance. If a section by the givenname already exists, DuplicateSectionError is raised. If thedefault section name is passed, ValueError is raised. The nameof the section must be a string; if not, TypeError is raised.

在 3.2 版更改: Non-string section names raise TypeError.

• hassection(_section)

• Indicates whether the named section is present in the configuration.The default section is not acknowledged.

• options(section)

• Return a list of options available in the specified section.

• hasoption(_section, option)

• If the given section exists, and contains the given option, returnTrue; otherwise return False. If the specifiedsection is None or an empty string, DEFAULT is assumed.

• read(filenames, encoding=None)

• Attempt to read and parse an iterable of filenames, returning a list offilenames which were successfully parsed.

If filenames is a string, a bytes object or apath-like object, it is treated asa single filename. If a file named in filenames cannot be opened, thatfile will be ignored. This is designed so that you can specify aniterable of potential configuration file locations (for example, thecurrent directory, the user's home directory, and some system-widedirectory), and all existing configuration files in the iterable will beread.

If none of the named files exist, the ConfigParserinstance will contain an empty dataset. An application which requiresinitial values to be loaded from a file should load the required file orfiles using read_file() before calling read() for anyoptional files:

import configparser, os
 
config = configparser.ConfigParser()
config.read_file(open('defaults.cfg'))
config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')],
            encoding='cp1250')

3.2 新版功能: The encoding parameter. Previously, all files were read using thedefault encoding for open().

3.6.1 新版功能: The filenames parameter accepts a path-like object.

3.7 新版功能: The filenames parameter accepts a bytes object.

• readfile(_f, source=None)
• Read and parse configuration data from f which must be an iterableyielding Unicode strings (for example files opened in text mode).

Optional argument source specifies the name of the file being read. Ifnot given and f has a name attribute, that is used forsource; the default is '<???>'.

3.2 新版功能: Replaces readfp().

• readstring(_string, source='')
• Parse configuration data from a string.

Optional argument source specifies a context-specific name of thestring passed. If not given, '<string>' is used. This shouldcommonly be a filesystem path or a URL.

3.2 新版功能.

• readdict(_dictionary, source='')
• Load configuration from any object that provides a dict-like items()method. Keys are section names, values are dictionaries with keys andvalues that should be present in the section. If the used dictionarytype 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 thedictionary passed. If not given, <dict> is used.

This method can be used to copy state between parsers.

3.2 新版功能.

• get(section, option, *, raw=False, vars=None[, fallback])
• Get an option value for the named section. If vars is provided, itmust be a dictionary. The option is looked up in vars (if provided),section, and in DEFAULTSECT in that order. If the key is not foundand fallback is provided, it is used as a fallback value. None canbe provided as a fallback value.

All the '%' interpolations are expanded in the return values, unlessthe raw argument is true. Values for interpolation keys are looked upin the same manner as the option.

在 3.2 版更改: Arguments raw, vars and fallback are keyword only to protectusers from trying to use the third argument as the fallback fallback(especially when using the mapping protocol).

• getint(section, option, *, raw=False, vars=None[, fallback])

• A convenience method which coerces the option in the specified section_to an integer. See get() for explanation of _raw, vars andfallback.

• 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 get() for explanation of _raw,vars and fallback.

• 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 toreturn True, and '0', 'no', 'false', and 'off', whichcause it to return False. These string values are checked in acase-insensitive manner. Any other value will cause it to raiseValueError. See get() for explanation of _raw, vars andfallback.

• 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 thegiven section. Optional arguments have the same meaning as for theget() method.

• set(section, option, value)

• If the given section exists, set the given option to the specified value;otherwise raise NoSectionError. option and value must bestrings; if not, TypeError is raised.

• write(fileobject, space_around_delimiters=True)

• Write a representation of the configuration to the specified fileobject, which must be opened in text mode (accepting strings). Thisrepresentation can be parsed by a future read() call. Ifspace_around_delimiters is true, delimiters betweenkeys and values are surrounded by spaces.

• removeoption(_section, option)

• Remove the specified option from the specified section. If thesection does not exist, raise NoSectionError. If the optionexisted to be removed, return True; otherwise returnFalse.

• removesection(_section)

• Remove the specified section from the configuration. If the section infact existed, return True. Otherwise return False.

• optionxform(option)

• Transforms the option name option as found in an input file or as passedin by client code to the form that should be used in the internalstructures. The default implementation returns a lower-case version ofoption; subclasses may override this or client code can set an attributeof this name on instances to affect this behavior.

You don't need to subclass the parser to use this method, you can alsoset it on an instance, to a function that takes a string argument andreturns a string. Setting it to str, for example, would make optionnames case sensitive:

cfgparser = ConfigParser()
cfgparser.optionxform = str

Note that when reading configuration files, whitespace around the optionnames is stripped before optionxform() is called.

• readfp(fp, filename=None)

3.2 版后已移除: Use read_file() instead.

在 3.2 版更改: readfp() now iterates on fp instead of calling fp.readline().

For existing code calling readfp() with arguments which don'tsupport iteration, the following generator may be used as a wrapperaround the file-like object:

def readline_generator(fp):
    line = fp.readline()
    while line:
        yield line
        line = fp.readline()

Instead of parser.readfp(fp) useparser.read_file(readline_generator(fp)).

• configparser.MAX_INTERPOLATION_DEPTH
• The maximum depth for recursive interpolation for get() when the _raw_parameter is false. This is relevant only when the default _interpolation_is used.

RawConfigParser Objects

• class configparser.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 ConfigParser. It has interpolationdisabled by default and allows for non-string section names, optionnames, and values via its unsafe add_section and set methods,as well as the legacy defaults= keyword argument handling.

注解

Consider using ConfigParser instead which checks types ofthe values to be stored internally. If you don't want interpolation, youcan use ConfigParser(interpolation=None).

• addsection(_section)
• Add a section named section to the instance. If a section by the givenname already exists, DuplicateSectionError is raised. If thedefault section name is passed, ValueError is raised.

Type of section is not checked which lets users create non-string namedsections. This behaviour is unsupported and may cause internal errors.

• set(section, option, value)
• If the given section exists, set the given option to the specified value;otherwise raise NoSectionError. While it is possible to useRawConfigParser (or ConfigParser with raw parametersset to true) for internal storage of non-string values, fullfunctionality (including interpolation and output to files) can only beachieved using string values.

This method lets users assign non-string values to keys internally. Thisbehaviour is unsupported and will cause errors when attempting to writeto a file or get it in non-raw mode. Use the mapping protocol APIwhich does not allow such assignments to take place.

异常

• exception configparser.Error
• Base class for all other configparser exceptions.

• exception configparser.NoSectionError
• Exception raised when a specified section is not found.

• exception configparser.DuplicateSectionError
• Exception raised if add_section() is called with the name of a sectionthat is already present or in strict parsers when a section if found morethan once in a single input file, string or dictionary.

3.2 新版功能: Optional source and lineno attributes and arguments toinit() were added.

• exception configparser.DuplicateOptionError
• Exception raised by strict parsers if a single option appears twice duringreading from a single file, string or dictionary. This catches misspellingsand case sensitivity-related errors, e.g. a dictionary may have two keysrepresenting the same case-insensitive configuration key.

• exception configparser.NoOptionError
• Exception raised when a specified option is not found in the specifiedsection.

• exception configparser.InterpolationError
• Base class for exceptions raised when problems occur performing stringinterpolation.

• exception configparser.InterpolationDepthError
• Exception raised when string interpolation cannot be completed because thenumber of iterations exceeds MAX_INTERPOLATION_DEPTH. Subclass ofInterpolationError.

• exception configparser.InterpolationMissingOptionError
• Exception raised when an option referenced from a value does not exist.Subclass of InterpolationError.

• exception configparser.InterpolationSyntaxError
• Exception raised when the source text into which substitutions are made doesnot conform to the required syntax. Subclass of InterpolationError.

• exception configparser.MissingSectionHeaderError
• Exception raised when attempting to parse a file which has no sectionheaders.

• exception configparser.ParsingError
• Exception raised when errors occur attempting to parse a file.

在 3.2 版更改: The filename attribute and init() argument were renamed tosource for consistency.

备注

• 1(1,2,3,4,5,6,7,8,9,10)
• Config parsers allow for heavy customization. If you are interested inchanging the behaviour outlined by the footnote reference, consult theCustomizing Parser Behaviour section.