configparser.py

来自「mallet是自然语言处理、机器学习领域的一个开源项目。」· Python 代码 · 共 473 行 · 第 1/2 页

"""Configuration file parser.

A setup file consists of sections, lead by a "[section]" header,
and followed by "name: value" entries, with continuations and such in
the style of RFC 822.

The option values can contain format strings which refer to other values in
the same section, or values in a special [DEFAULT] section.

For example:

    something: %(dir)s/whatever

would resolve the "%(dir)s" to the value of dir.  All reference
expansions are done late, on demand.

Intrinsic defaults can be specified by passing them into the
ConfigParser constructor as a dictionary.

class:

ConfigParser -- responsible for for parsing a list of
                configuration files, and managing the parsed database.

    methods:

    __init__(defaults=None)
        create the parser and specify a dictionary of intrinsic defaults.  The
        keys must be strings, the values must be appropriate for %()s string
        interpolation.  Note that `__name__' is always an intrinsic default;
        it's value is the section's name.

    sections()
        return all the configuration section names, sans DEFAULT

    has_section(section)
        return whether the given section exists

    has_option(section, option)
        return whether the given option exists in the given section

    options(section)
        return list of configuration options for the named section

    read(filenames)
        read and parse the list of named configuration files, given by
        name.  A single filename is also allowed.  Non-existing files
        are ignored.

    readfp(fp, filename=None)
        read and parse one configuration file, given as a file object.
        The filename defaults to fp.name; it is only used in error
        messages (if fp has no `name' attribute, the string `<???>' is used).

    get(section, option, raw=0, vars=None)
        return a string value for the named option.  All % interpolations are
        expanded in the return values, based on the defaults passed into the
        constructor and the DEFAULT section.  Additional substitutions may be
        provided using the `vars' argument, which must be a dictionary whose
        contents override any pre-existing defaults.

    getint(section, options)
        like get(), but convert value to an integer

    getfloat(section, options)
        like get(), but convert value to a float

    getboolean(section, options)
        like get(), but convert value to a boolean (currently case
        insensitively defined as 0, false, no, off for 0, and 1, true,
        yes, on for 1).  Returns 0 or 1.

    remove_section(section)
        remove the given file section and all its options

    remove_option(section, option)
        remove the given option from the given section

    set(section, option, value)
        set the given option

    write(fp)
        write the configuration state in .ini format
"""

import re
import types

__all__ = ["NoSectionError","DuplicateSectionError","NoOptionError",
           "InterpolationError","InterpolationDepthError","ParsingError",
           "MissingSectionHeaderError","ConfigParser",
           "DEFAULTSECT", "MAX_INTERPOLATION_DEPTH"]

DEFAULTSECT = "DEFAULT"

MAX_INTERPOLATION_DEPTH = 10



# exception classes
class Error(Exception):
    def __init__(self, msg=''):
        self._msg = msg
        Exception.__init__(self, msg)
    def __repr__(self):
        return self._msg
    __str__ = __repr__

class NoSectionError(Error):
    def __init__(self, section):
        Error.__init__(self, 'No section: %s' % section)
        self.section = section

class DuplicateSectionError(Error):
    def __init__(self, section):
        Error.__init__(self, "Section %s already exists" % section)
        self.section = section

class NoOptionError(Error):
    def __init__(self, option, section):
        Error.__init__(self, "No option `%s' in section: %s" %
                       (option, section))
        self.option = option
        self.section = section

class InterpolationError(Error):
    def __init__(self, reference, option, section, rawval):
        Error.__init__(self,
                       "Bad value substitution:\n"
                       "\tsection: [%s]\n"
                       "\toption : %s\n"
                       "\tkey    : %s\n"
                       "\trawval : %s\n"
                       % (section, option, reference, rawval))
        self.reference = reference
        self.option = option
        self.section = section

class InterpolationDepthError(Error):
    def __init__(self, option, section, rawval):
        Error.__init__(self,
                       "Value interpolation too deeply recursive:\n"
                       "\tsection: [%s]\n"
                       "\toption : %s\n"
                       "\trawval : %s\n"
                       % (section, option, rawval))
        self.option = option
        self.section = section

class ParsingError(Error):
    def __init__(self, filename):
        Error.__init__(self, 'File contains parsing errors: %s' % filename)
        self.filename = filename
        self.errors = []

    def append(self, lineno, line):
        self.errors.append((lineno, line))
        self._msg = self._msg + '\n\t[line %2d]: %s' % (lineno, line)

class MissingSectionHeaderError(ParsingError):
    def __init__(self, filename, lineno, line):
        Error.__init__(
            self,
            'File contains no section headers.\nfile: %s, line: %d\n%s' %
            (filename, lineno, line))
        self.filename = filename
        self.lineno = lineno
        self.line = line



class ConfigParser:
    def __init__(self, defaults=None):
        self.__sections = {}
        if defaults is None:
            self.__defaults = {}
        else:
            self.__defaults = defaults

    def defaults(self):
        return self.__defaults

    def sections(self):
        """Return a list of section names, excluding [DEFAULT]"""
        # self.__sections will never have [DEFAULT] in it
        return self.__sections.keys()

    def add_section(self, section):
        """Create a new section in the configuration.

        Raise DuplicateSectionError if a section by the specified name
        already exists.
        """
        if section in self.__sections:
            raise DuplicateSectionError(section)
        self.__sections[section] = {}

    def has_section(self, section):
        """Indicate whether the named section is present in the configuration.

        The DEFAULT section is not acknowledged.
        """
        return section in self.__sections

    def options(self, section):
        """Return a list of option names for the given section name."""
        try:
            opts = self.__sections[section].copy()
        except KeyError:
            raise NoSectionError(section)
        opts.update(self.__defaults)
        if '__name__' in opts:
            del opts['__name__']
        return opts.keys()

    def read(self, filenames):
        """Read and parse a filename or a list of filenames.

        Files that cannot be opened are silently ignored; this is
        designed so that you can specify a list of potential
        configuration file locations (e.g. current directory, user's
        home directory, systemwide directory), and all existing
        configuration files in the list will be read.  A single
        filename may also be given.
        """
        if isinstance(filenames, types.StringTypes):
            filenames = [filenames]
        for filename in filenames:
            try:
                fp = open(filename)
            except IOError:
                continue
            self.__read(fp, filename)
            fp.close()

    def readfp(self, fp, filename=None):
        """Like read() but the argument must be a file-like object.