13.2. `ConfigParser` — 配置文件剖析器 ¶

注意

The ConfigParser module has been renamed to configparser in Python 3. The 2to3 tool will automatically adapt imports when converting your sources to Python 3.

此模块定义类 ConfigParser 。 ConfigParser class implements a basic configuration file parser language which provides a structure similar to what you would find on Microsoft Windows INI files. You can use this to write Python programs which can be customized by end users easily.

注意

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

另请参阅

模块 shlex
模块 json: The json module implements a subset of JavaScript syntax which can also be used for this purpose.

The configuration file consists of sections, led by a [section] header and followed by name: value entries, with continuations in the style of RFC 822 (see section 3.1.1, “LONG HEADER FIELDS”); name=value is also accepted. Note that leading whitespace is removed from values. The optional values can contain format strings which refer to other values in the same section, or values in a special DEFAULT section. Additional defaults can be provided on initialization and retrieval. Lines beginning with '#' or ';' are ignored and may be used to provide comments.

Configuration files may include comments, prefixed by specific characters ( # and ; ). 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, only ; starts an inline comment, while # does not.)

On top of the core functionality, SafeConfigParser supports interpolation. This means values can contain format strings which refer to other values in the same section, or values in a special DEFAULT section. Additional defaults can be provided on initialization.

例如：

[My Section]
foodir: %(dir)s/whatever
dir=frob
long: this value continues
   in the next line

would resolve the %(dir)s to the value of dir ( frob in this case). All reference expansions are done on demand.

Default values can be specified by passing them into the ConfigParser constructor as a dictionary. Additional defaults may be passed into the get() method which will override all others.

Sections are normally stored in a built-in dictionary. An alternative dictionary type can be passed to the ConfigParser constructor. For example, if a dictionary type is passed that sorts its keys, the sections will be sorted on write-back, as will be the keys within each section.

class ConfigParser. RawConfigParser ( [ defaults [ , dict_type [ , allow_no_value ] ] ] ) ¶

class ConfigParser. ConfigParser ( [ defaults [ , dict_type [ , allow_no_value ] ] ] ) ¶

class ConfigParser. SafeConfigParser ( [ defaults [ , dict_type [ , allow_no_value ] ] ] ) ¶

exception ConfigParser. Error ¶

exception ConfigParser. NoSectionError ¶

exception ConfigParser. DuplicateSectionError ¶

exception ConfigParser. NoOptionError ¶

exception ConfigParser. InterpolationError ¶

exception ConfigParser. InterpolationDepthError ¶

exception ConfigParser. InterpolationMissingOptionError ¶

exception ConfigParser. InterpolationSyntaxError ¶

exception ConfigParser. MissingSectionHeaderError ¶

exception ConfigParser. ParsingError ¶

ConfigParser. MAX_INTERPOLATION_DEPTH ¶

另请参阅

模块 shlex

13.2.1. RawConfigParser 对象 ¶

RawConfigParser 实例具有下列方法：

RawConfigParser. defaults ( ) ¶

RawConfigParser. sections ( ) ¶

RawConfigParser. add_section ( section ) ¶

RawConfigParser. has_section ( section ) ¶

RawConfigParser. 选项 ( section ) ¶

RawConfigParser. has_option ( section , option ) ¶

RawConfigParser. read ( filenames ) ¶

RawConfigParser. readfp ( fp [ , filename ] ) ¶

RawConfigParser. get ( section , option ) ¶

RawConfigParser. getint ( section , option ) ¶: A convenience method which coerces the option 以指定 section to an integer.

RawConfigParser. getfloat ( section , option ) ¶: A convenience method which coerces the option 以指定 section to a floating point number.

RawConfigParser. getboolean ( section , option ) ¶: A convenience method which coerces the option 以指定 section to a Boolean value. Note that the accepted values for the option are "1" , "yes" , "true" ，和 "on" , which cause this method to return True ，和 "0" , "no" , "false" ，和 "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 ValueError .

RawConfigParser. 项 ( section ) ¶: 返回列表化的 (name, value) pairs for each option in the given section .

RawConfigParser. set ( section , option , 值 ) ¶

If the given section exists, set the given option to the specified value; otherwise raise NoSectionError . While it is possible to use RawConfigParser (或 ConfigParser with raw parameters set to true) for internal storage of non-string values, full functionality (including interpolation and output to files) can only be achieved using string values.

New in version 1.6.

RawConfigParser. write ( fileobject ) ¶

Write a representation of the configuration to the specified file object. This representation can be parsed by a future read() 调用。

New in version 1.6.

RawConfigParser. remove_option ( section , option ) ¶

Remove the specified option 从指定 section . If the section does not exist, raise NoSectionError . If the option existed to be removed, return True ；否则返回 False .

New in version 1.6.

RawConfigParser. remove_section ( section ) ¶: Remove the specified section from the configuration. If the section in fact existed, return True . Otherwise return False .

RawConfigParser. optionxform ( option ) ¶

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

You don’t necessarily need to subclass a ConfigParser to use this method, you can also re-set it on an instance, to a function that takes a string argument. Setting it to str , for example, would make option names case sensitive:

cfgparser = ConfigParser()
...
cfgparser.optionxform = str

Note that when reading configuration files, whitespace around the option names are stripped before optionxform() 被调用。

13.2.2. ConfigParser 对象 ¶

The ConfigParser class extends some methods of the RawConfigParser interface, adding some optional arguments.

ConfigParser. get ( section , option [ , raw [ , vars ] ] ) ¶

Get an option value for the named section 。若 vars is provided, it must be a dictionary. The option is looked up in vars (if provided), section , and in defaults in that order.

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

ConfigParser. 项 ( section [ , raw [ , vars ] ] ) ¶

返回列表化的 (name, value) pairs for each option in the given section . Optional arguments have the same meaning as for the get() 方法。

2.3 版新增。

13.2.3. SafeConfigParser Objects ¶

The SafeConfigParser class implements the same extended interface as ConfigParser , with the following addition:

SafeConfigParser. set ( section , option , 值 ) ¶

If the given section exists, set the given option to the specified value; otherwise raise NoSectionError . value must be a string ( str or unicode ); if not, TypeError 被引发。

2.4 版新增。

13.2.4. 范例 ¶

写入配置文件的范例：

import ConfigParser
config = ConfigParser.RawConfigParser()
# When adding sections or items, add them in the reverse order of
# how you want them to be displayed in the actual file.
# In addition, please note that using RawConfigParser's and the raw
# mode of ConfigParser's respective 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. SafeConfigParser 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', 'wb') 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, you will need to use a ConfigParser or SafeConfigParser :

import ConfigParser
config = ConfigParser.ConfigParser()
config.read('example.cfg')
# Set the third, optional argument of get to 1 if you wish to use raw mode.
print config.get('Section1', 'foo', 0)  # -> "Python is fun!"
print config.get('Section1', 'foo', 1)  # -> "%(bar)s is %(baz)s!"
# The optional fourth argument is a dict with members that will take
# precedence in interpolation.
print config.get('Section1', 'foo', 0, {'bar': 'Documentation',
                                        'baz': 'evil'})

Defaults are available in all three types of ConfigParsers. They are used in interpolation if an option used is not defined elsewhere.

import ConfigParser
# New instance with 'bar' and 'baz' defaulting to 'Life' and 'hard' each
config = ConfigParser.SafeConfigParser({'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!"

函数 opt_move below can be used to move options between sections:

def opt_move(config, section1, section2, option):
    try:
        config.set(section2, option, config.get(section1, option, 1))
    except ConfigParser.NoSectionError:
        # Create non-existent section
        config.add_section(section2)
        opt_move(config, section1, section2, option)
    else:
        config.remove_option(section1, option)

Some configuration files are known to include settings without values, but which otherwise conform to the syntax supported by ConfigParser 。 allow_no_value parameter to the constructor can be used to indicate that such values should be accepted:

>>> import ConfigParser
>>> import io
>>> sample_config = """
... [mysqld]
... user = mysql
... pid-file = /var/run/mysqld/mysqld.pid
... skip-external-locking
... old_passwords = 1
... skip-bdb
... skip-innodb
... """
>>> config = ConfigParser.RawConfigParser(allow_no_value=True)
>>> config.readfp(io.BytesIO(sample_config))
>>> # Settings with values are treated as before:
>>> config.get("mysqld", "user")
'mysql'
>>> # Settings without values provide None:
>>> config.get("mysqld", "skip-bdb")
>>> # Settings which aren't specified still raise an error:
>>> config.get("mysqld", "does-not-exist")
Traceback (most recent call last):
  ...
ConfigParser.NoOptionError: No option 'does-not-exist' in section: 'mysqld'

13.2. ConfigParser — 配置文件剖析器 ¶

13.2.1. RawConfigParser 对象 ¶

13.2.2. ConfigParser 对象 ¶

13.2.3. SafeConfigParser Objects ¶

13.2.4. 范例 ¶

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13.2. `ConfigParser` — 配置文件剖析器 ¶