configparser
--- 設定檔剖析器¶
This module provides theConfigParser
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.
備註
This library doesnot interpret or write the value-type prefixes used inthe Windows Registry extended version of INI syntax.
也參考
tomllib
模組TOML is a well-specified format for application configuration files.It is specifically designed to be an improved version of INI.
shlex
模組Support for creating Unix shell-like mini-languages which can alsobe used for application configuration files.
json
模組The
json
module implements a subset of JavaScript syntax which issometimes used for configuration, but does not support comments.
Quick Start¶
Let's take a very basic configuration file that looks like this:
[DEFAULT]ServerAliveInterval=45Compression=yesCompressionLevel=9ForwardX11=yes[forge.example]User=hg[topsecret.server.example]Port=50022ForwardX11=no
The structure of INI files is describedin 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.
>>>importconfigparser>>>config=configparser.ConfigParser()>>>config['DEFAULT']={'ServerAliveInterval':'45',...'Compression':'yes',...'CompressionLevel':'9'}>>>config['forge.example']={}>>>config['forge.example']['User']='hg'>>>config['topsecret.server.example']={}>>>topsecret=config['topsecret.server.example']>>>topsecret['Port']='50022'# mutates the parser>>>topsecret['ForwardX11']='no'# same here>>>config['DEFAULT']['ForwardX11']='yes'>>>withopen('example.ini','w')asconfigfile:...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()['forge.example', 'topsecret.server.example']>>>'forge.example'inconfigTrue>>>'python.org'inconfigFalse>>>config['forge.example']['User']'hg'>>>config['DEFAULT']['Compression']'yes'>>>topsecret=config['topsecret.server.example']>>>topsecret['ForwardX11']'no'>>>topsecret['Port']'50022'>>>forkeyinconfig['forge.example']:...print(key)usercompressionlevelserveraliveintervalcompressionforwardx11>>>config['forge.example']['ForwardX11']'yes'
As we can see above, the API is pretty straightforward. The only bit of magicinvolves theDEFAULT
section which provides default values for all othersections[1]. Note also that keys in sections arecase-insensitive and stored in lowercase[1].
It is possible to read several configurations into a singleConfigParser
, where the most recently added configuration has thehighest priority. Any conflicting keys are taken from the more recentconfiguration while the previously existing keys are retained. The examplebelow reads in anoverride.ini
file, which will override any conflictingkeys from theexample.ini
file.
[DEFAULT]ServerAliveInterval=-1
>>>config_override=configparser.ConfigParser()>>>config_override['DEFAULT']={'ServerAliveInterval':'-1'}>>>withopen('override.ini','w')asconfigfile:...config_override.write(configfile)...>>>config_override=configparser.ConfigParser()>>>config_override.read(['example.ini','override.ini'])['example.ini', 'override.ini']>>>print(config_override.get('DEFAULT','ServerAliveInterval'))-1
This behaviour is equivalent to aConfigParser.read()
call with severalfiles passed to thefilenames parameter.
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 tobool()
would do no goodsincebool('False')
is stillTrue
. This is why config parsers alsoprovidegetboolean()
. 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['forge.example'].getboolean('ForwardX11')True>>>config.getboolean('forge.example','Compression')True
Apart fromgetboolean()
, config parsers alsoprovide equivalentgetint()
andgetfloat()
methods. You can register your ownconverters and customize the provided ones.[1]
Fallback Values¶
As with a dictionary, you can use a section'sget()
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.example'
, 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-levelget()
methodprovides a custom, more complex interface, maintained for backwardscompatibility. When using this method, a fallback value can be provided viathefallback
keyword-only argument:
>>>config.get('forge.example','monster',...fallback='No such things as monsters')'No such things as monsters'
The samefallback
argument can be used with thegetint()
,getfloat()
andgetboolean()
methods, for example:
>>>'BatchMode'intopsecretFalse>>>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 not[1]. Leading and trailing whitespace is removed from keys and values.Values can be omitted if the parser is configured to allow it[1],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.
By default, a valid section name can be any string that does not contain '\n'.To change this, seeConfigParser.SECTCRE
.
The first section name may be omitted if the parser is configured to allow anunnamed top level section withallow_unnamed_section=True
. In this case,the keys/values may be retrieved byUNNAMED_SECTION
as inconfig[UNNAMED_SECTION]
.
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]
舉例來說:
[Simple Values]key=valuespaces in keys=allowedspaces in values=allowed as wellspaces around the delimiter=obviouslyyou can also use:to delimit keys from values[All Values Are Strings]values like this:1000000or this:3.14159265359are they treated as numbers?:nointegers, floats and booleans are held as:stringscan use the API to get converted values directly:true[Multiline Values]chorus:I'm a lumberjack, and I'm okayI sleep all night and I work all day[No Values]key_without_valueempty 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=Truedoes_that_mean_anything_special=Falsepurpose=formatting for readabilitymultiline_values=arehandled just fine aslong as they are indenteddeeper than the first lineof a value# Did I mention we can indent comments, too?
Unnamed Sections¶
The name of the first section (or unique) may be omitted and valuesretrieved by theUNNAMED_SECTION
attribute.
>>>config="""...option = value......[ Section 2 ]...another = val...""">>>unnamed=configparser.ConfigParser(allow_unnamed_section=True)>>>unnamed.read_string(config)>>>unnamed.get(configparser.UNNAMED_SECTION,'option')'value'
Interpolation of values¶
On top of the core functionality,ConfigParser
supportsinterpolation. This means values can be preprocessed before returning themfromget()
calls.
- classconfigparser.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.舉例來說:
[Paths]home_dir:/Usersmy_dir:%(home_dir)s/lumberjackmy_pictures:%(my_dir)s/Pictures[Escape]# use a %% to escape the % sign (% is the only character that needs to be escaped):gain:80%%
In the example above,
ConfigParser
withinterpolation 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 toNone
, the parser would simply return%(my_dir)s/Pictures
as the value ofmy_pictures
and%(home_dir)s/lumberjack
as the value ofmy_dir
.
- classconfigparser.ExtendedInterpolation¶
An alternative handler for interpolation which implements a more advancedsyntax, used for instance in
zc.buildout
. Extended interpolation isusing${section:option}
to denote a value from a foreign section.Interpolation can span multiple levels. For convenience, if thesection:
part is omitted, interpolation defaults to the current section(and possibly the default values from the special section).For example, the configuration specified above with basic interpolation,would look like this with extended interpolation:
[Paths]home_dir:/Usersmy_dir:${home_dir}/lumberjackmy_pictures:${my_dir}/Pictures[Escape]# use a $$ to escape the $ sign ($ is the only character that needs to be escaped):cost:$$80
Values from other sections can be fetched as well:
[Common]home_dir:/Userslibrary_dir:/Librarysystem_dir:/Systemmacports_dir:/opt/local[Frameworks]Python:3.2path:${Common:system_dir}/Library/Frameworks/[Arthur]nickname:Two Shedslast_name:Jacksonmy_dir:${Common:home_dir}/twoshedsmy_pictures:${my_dir}/Picturespython_dir:${Frameworks:path}/Python/Versions/${Frameworks:Python}
Mapping Protocol Access¶
在 3.2 版被加入.
Mapping protocol access is a generic name for functionality that enables usingcustom objects as if they were dictionaries. In case ofconfigparser
,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 manner[1]. E.g.
foroptioninparser["section"]
yields onlyoptionxform
'edoption key names. This means lowercased keys by default. At the same time,for a section that holds the key'a'
, both expressions returnTrue
:"a"inparser["section"]"A"inparser["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 aKeyError
.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 isnota fallback value. Note however that the section-levelget()
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 ofoption,value pairs fora specifiedsection
, 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, use
read_dict()
before you read the actual file.dict_type, default value:
dict
This option has a major impact on how the mapping protocol will behave and howthe written configuration files look. With the standard dictionary, everysection is stored in the order they were added to the parser. Same goes foroptions within sections.
An alternative dictionary type can be used for example to sort sections andoptions on write-back.
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. 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']>>>[optionforoptioninparser['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:>>>importconfigparser>>>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 thespace_around_delimiters argument to
ConfigParser.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) whereasinline_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 版的變更:In previous versions of
configparser
behaviour matchedcomment_prefixes=('#',';')
andinline_comment_prefixes=(';',)
.Please note that config parsers don't support escaping of comment prefixes sousinginline_comment_prefixes may prevent users from specifying optionvalues with characters used as comment prefixes. When in doubt, avoidsettinginline_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:
>>>fromconfigparserimportConfigParser,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_extensionanother_extensionyet_another_extension>>>print(parser['hashes']['interpolation not necessary'])if # is not at line start>>>print(parser['hashes']['even in multiline values'])line #1line #2line #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 (usingread_file()
,read_string()
orread_dict()
). It is recommended to use strictparsers in new applications.在 3.2 版的變更: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=multilinevalue with a gotchathis=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
andthis
.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 theinterpolation argument.
None
can be used to turn offinterpolation completely,ExtendedInterpolation()
provides a moreadvanced variant inspired byzc.buildout
. More on the subject in thededicated documentation section.RawConfigParser
has a default value ofNone
.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 thegetdecimal()
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 valuesTrue
:'1'
,'yes'
,'true'
,'on'
and the following valuesFalse
:'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=lambdaoption:option>>>custom.read_string(config)>>>list(custom['Section1'].keys())['Key']>>>list(custom['Section2'].keys())['AnotherKey']
備註
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:>>>importre>>>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']
備註
While ConfigParser objects also use an
OPTCRE
attribute for recognizingoption lines, it's not recommended to override it because that wouldinterfere with constructor optionsallow_no_value anddelimiters.
Legacy API Examples¶
Mainly because of backwards compatibility concerns,configparser
provides also a legacy API with explicitget
/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:
importconfigparserconfig=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'withopen('example.cfg','w')asconfigfile:config.write(configfile)
An example of reading the configuration file again:
importconfigparserconfig=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 typesa_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().ifconfig.getboolean('Section1','a_bool'):print(config.get('Section1','foo'))
To get interpolation, useConfigParser
:
importconfigparsercfg=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 valueprint(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.
importconfigparser# New instance with 'bar' and 'baz' defaulting to 'Life' and 'hard' eachconfig=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 物件¶
- classconfigparser.ConfigParser(defaults=None,dict_type=dict,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={},allow_unnamed_section=False)¶
The main configuration parser. Whendefaults is given, it is initializedinto the dictionary of intrinsic defaults. Whendict_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.
Whendelimiters is given, it is used as the set of substrings thatdivide keys from values. Whencomment_prefixes is given, it will be usedas the set of substrings that prefix comments in otherwise empty lines.Comments can be indented. Wheninline_comment_prefixes is given, it willbe used as the set of substrings that prefix comments in non-empty lines.
Whenstrict is
True
(the default), the parser won't allow forany section or option duplicates while reading from a single source (file,string or dictionary), raisingDuplicateSectionError
orDuplicateOptionError
. Whenempty_lines_in_values isFalse
(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.Whenallow_no_value isTrue
(default:False
), options withoutvalues are accepted; the value held for these isNone
and they areserialized without the trailing delimiter.Whendefault_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 atruntime using thedefault_section
instance attribute. This won'tre-evaluate an already parsed config file, but will be used when writingparsed settings to a new config file.Interpolation behaviour may be customized by providing a custom handlerthrough theinterpolation argument.
None
can be used to turn offinterpolation completely,ExtendedInterpolation()
provides a moreadvanced variant inspired byzc.buildout
. More on the subject in thededicated documentation section.All option names used in interpolation will be passed through the
optionxform()
method just like any other option name reference. Forexample, using the default implementation ofoptionxform()
(whichconverts option names to lower case), the valuesfoo%(bar)s
andfoo%(BAR)s
are equivalent.Whenconverters 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.Whenallow_unnamed_section is
True
(default:False
),the first section name can be omitted. See the"Unnamed Sections" section.It is possible to read several configurations into a single
ConfigParser
, where the most recently added configuration has thehighest priority. Any conflicting keys are taken from the more recentconfiguration while the previously existing keys are retained. The examplebelow reads in anoverride.ini
file, which will override any conflictingkeys from theexample.ini
file.[DEFAULT]ServerAliveInterval=-1
>>>config_override=configparser.ConfigParser()>>>config_override['DEFAULT']={'ServerAliveInterval':'-1'}>>>withopen('override.ini','w')asconfigfile:...config_override.write(configfile)...>>>config_override=configparser.ConfigParser()>>>config_override.read(['example.ini','override.ini'])['example.ini', 'override.ini']>>>print(config_override.get('DEFAULT','ServerAliveInterval'))-1
在 3.1 版的變更:The defaultdict_type is
collections.OrderedDict
.在 3.2 版的變更:allow_no_value,delimiters,comment_prefixes,strict,empty_lines_in_values,default_section andinterpolation wereadded.
在 3.5 版的變更:新增converters 引數。
在 3.7 版的變更:Thedefaults argument is read with
read_dict()
,providing consistent behavior across the parser: non-stringkeys and values are implicitly converted to strings.在 3.8 版的變更:The defaultdict_type is
dict
, since it now preservesinsertion order.在 3.13 版的變更:Raise a
MultilineContinuationError
whenallow_no_value isTrue
, and a key without a value is continued with an indented line.在 3.13 版的變更:新增allow_unnamed_section 引數。
- defaults()¶
Return a dictionary containing the instance-wide defaults.
- sections()¶
Return a list of the sections available; thedefault section is notincluded in the list.
- add_section(section)¶
Add a section namedsection 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 版的變更:Non-string section names raise
TypeError
.
- has_section(section)¶
Indicates whether the namedsection is present in the configuration.Thedefault section is not acknowledged.
- options(section)¶
Return a list of options available in the specifiedsection.
- has_option(section,option)¶
If the givensection exists, and contains the givenoption, return
True
; otherwise returnFalse
. If the specifiedsection isNone
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.
Iffilenames is a string, a
bytes
object or apath-like object, it is treated asa single filename. If a file named infilenames 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
ConfigParser
instance will contain an empty dataset. An application which requiresinitial values to be loaded from a file should load the required file orfiles usingread_file()
before callingread()
for anyoptional files:importconfigparser,osconfig=configparser.ConfigParser()config.read_file(open('defaults.cfg'))config.read(['site.cfg',os.path.expanduser('~/.myapp.cfg')],encoding='cp1250')
在 3.2 版的變更:Added theencoding parameter.Previously, all files were read using the default encoding for
open()
.在 3.6.1 版的變更:Thefilenames parameter accepts apath-like object.
在 3.7 版的變更:Thefilenames parameter accepts a
bytes
object.
- read_file(f,source=None)¶
Read and parse configuration data fromf which must be an iterableyielding Unicode strings (for example files opened in text mode).
Optional argumentsource specifies the name of the file being read. Ifnot given andf has a
name
attribute, that is used forsource; the default is'<???>'
.在 3.2 版被加入:取代
readfp()
。
- read_string(string,source='<string>')¶
Parse configuration data from a string.
Optional argumentsource specifies a context-specific name of thestring passed. If not given,
'<string>'
is used. This shouldcommonly be a filesystem path or a URL.在 3.2 版被加入.
- read_dict(dictionary,source='<dict>')¶
Load configuration from any object that provides a dict-like
items()
method. Keys are section names, values are dictionaries with keys 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 argumentsource specifies a context-specific name of thedictionary passed. If not given,
<dict>
is used.This method can be used to copy state between parsers.
在 3.2 版被加入.
- get(section,option,*,raw=False,vars=None[,fallback])¶
Get anoption value for the namedsection. Ifvars is provided, itmust be a dictionary. Theoption is looked up invars (if provided),section, and inDEFAULTSECT in that order. If the key is not foundandfallback is provided, it is used as a fallback value.
None
canbe provided as afallback value.All the
'%'
interpolations are expanded in the return values, unlesstheraw argument is true. Values for interpolation keys are looked upin the same manner as the option.在 3.2 版的變更:Argumentsraw,vars andfallback are keyword only to protectusers from trying to use the third argument as thefallback fallback(especially when using the mapping protocol).
- getint(section,option,*,raw=False,vars=None[,fallback])¶
A convenience method which coerces theoption in the specifiedsectionto an integer. See
get()
for explanation ofraw,vars andfallback.
- getfloat(section,option,*,raw=False,vars=None[,fallback])¶
A convenience method which coerces theoption in the specifiedsectionto a floating-point number. See
get()
for explanation ofraw,vars andfallback.
- getboolean(section,option,*,raw=False,vars=None[,fallback])¶
A convenience method which coerces theoption in the specifiedsectionto a Boolean value. Note that the accepted values for the option are
'1'
,'yes'
,'true'
, and'on'
, which cause this method toreturnTrue
, and'0'
,'no'
,'false'
, and'off'
, whichcause it to returnFalse
. These string values are checked in acase-insensitive manner. Any other value will cause it to raiseValueError
. Seeget()
for explanation ofraw,vars andfallback.
- items(raw=False,vars=None)¶
- items(section,raw=False,vars=None)
Whensection is not given, return a list ofsection_name,section_proxy pairs, including DEFAULTSECT.
Otherwise, return a list ofname,value pairs for the options in thegivensection. Optional arguments have the same meaning as for the
get()
method.在 3.8 版的變更:Items present invars no longer appear in the result. The previousbehaviour mixed actual parser options with variables provided forinterpolation.
- set(section,option,value)¶
If the given section exists, set the given option to the specified value;otherwise raise
NoSectionError
.option andvalue must bestrings; if not,TypeError
is raised.
- write(fileobject,space_around_delimiters=True)¶
Write a representation of the configuration to the specifiedfileobject, 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.
備註
Comments in the original configuration file are not preserved whenwriting the configuration back.What is considered a comment, depends on the given values forcomment_prefix andinline_comment_prefix.
- remove_option(section,option)¶
Remove the specifiedoption from the specifiedsection. If thesection does not exist, raise
NoSectionError
. If the optionexisted to be removed, returnTrue
; otherwise returnFalse
.
- remove_section(section)¶
Remove the specifiedsection from the configuration. If the section infact existed, return
True
. Otherwise returnFalse
.
- optionxform(option)¶
Transforms the option nameoption 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.
- configparser.UNNAMED_SECTION¶
A special object representing a section name used to reference the unnamed section (seeUnnamed Sections).
RawConfigParser 物件¶
- classconfigparser.RawConfigParser(defaults=None,dict_type=dict,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={},allow_unnamed_section=False)¶
Legacy variant of the
ConfigParser
. It has interpolationdisabled by default and allows for non-string section names, optionnames, and values via its unsafeadd_section
andset
methods,as well as the legacydefaults=
keyword argument handling.在 3.2 版的變更:allow_no_value,delimiters,comment_prefixes,strict,empty_lines_in_values,default_section andinterpolation wereadded.
在 3.5 版的變更:新增converters 引數。
在 3.8 版的變更:The defaultdict_type is
dict
, since it now preservesinsertion order.在 3.13 版的變更:新增allow_unnamed_section 引數。
備註
Consider using
ConfigParser
instead which checks types ofthe values to be stored internally. If you don't want interpolation, youcan useConfigParser(interpolation=None)
.- add_section(section)¶
Add a section namedsection to the instance. If a section by the givenname already exists,
DuplicateSectionError
is raised. If thedefault section name is passed,ValueError
is raised.Type ofsection 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
(orConfigParser
withraw parametersset to true) forinternal 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.
例外¶
- exceptionconfigparser.Error¶
Base class for all other
configparser
exceptions.
- exceptionconfigparser.NoSectionError¶
Exception raised when a specified section is not found.
- exceptionconfigparser.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.在 3.2 版的變更:Added the optionalsource andlineno attributes and parameters to
__init__()
.
- exceptionconfigparser.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.
- exceptionconfigparser.NoOptionError¶
Exception raised when a specified option is not found in the specifiedsection.
- exceptionconfigparser.InterpolationError¶
Base class for exceptions raised when problems occur performing stringinterpolation.
- exceptionconfigparser.InterpolationDepthError¶
Exception raised when string interpolation cannot be completed because thenumber of iterations exceeds
MAX_INTERPOLATION_DEPTH
. Subclass ofInterpolationError
.
- exceptionconfigparser.InterpolationMissingOptionError¶
Exception raised when an option referenced from a value does not exist.Subclass of
InterpolationError
.
- exceptionconfigparser.InterpolationSyntaxError¶
Exception raised when the source text into which substitutions are made doesnot conform to the required syntax. Subclass of
InterpolationError
.
- exceptionconfigparser.MissingSectionHeaderError¶
Exception raised when attempting to parse a file which has no sectionheaders.
- exceptionconfigparser.ParsingError¶
Exception raised when errors occur attempting to parse a file.
在 3.12 版的變更:The
filename
attribute and__init__()
constructor argument wereremoved. They have been available using the namesource
since 3.2.
- exceptionconfigparser.MultilineContinuationError¶
Exception raised when a key without a corresponding value is continued withan indented line.
在 3.13 版被加入.
註腳
[1](1,2,3,4,5,6,7,8,9,10,11)Config parsers allow for heavy customization. If you are interested inchanging the behaviour outlined by the footnote reference, consult theCustomizing Parser Behaviour section.