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

        The `fp' argument must have a `readline' method.  Optional
        second argument is the `filename', which if not given, is
        taken from fp.name.  If fp has no `name' attribute, `<???>' is
        used.

        """
        if filename is None:
            try:
                filename = fp.name
            except AttributeError:
                filename = '<???>'
        self.__read(fp, filename)

    def get(self, section, option, raw=0, vars=None):
        """Get an option value for a given section.

        All % interpolations are expanded in the return values, based on the
        defaults passed into the constructor, unless the optional argument
        `raw' is true.  Additional substitutions may be provided using the
        `vars' argument, which must be a dictionary whose contents overrides
        any pre-existing defaults.

        The section DEFAULT is special.
        """
        d = self.__defaults.copy()
        try:
            d.update(self.__sections[section])
        except KeyError:
            if section != DEFAULTSECT:
                raise NoSectionError(section)
        # Update with the entry specific variables
        if vars is not None:
            d.update(vars)
        option = self.optionxform(option)
        try:
            value = d[option]
        except KeyError:
            raise NoOptionError(option, section)

        if raw:
            return value
        return self._interpolate(section, option, value, d)

    def _interpolate(self, section, option, rawval, vars):
        # do the string interpolation
        value = rawval
        depth = MAX_INTERPOLATION_DEPTH
        while depth:                    # Loop through this until it's done
            depth -= 1
            if value.find("%(") != -1:
                try:
                    value = value % vars
                except KeyError, key:
                    raise InterpolationError(key, option, section, rawval)
            else:
                break
        if value.find("%(") != -1:
            raise InterpolationDepthError(option, section, rawval)
        return value

    def __get(self, section, conv, option):
        return conv(self.get(section, option))

    def getint(self, section, option):
        return self.__get(section, int, option)

    def getfloat(self, section, option):
        return self.__get(section, float, option)

    _boolean_states = {'1': True, 'yes': True, 'true': True, 'on': True,
                       '0': False, 'no': False, 'false': False, 'off': False}

    def getboolean(self, section, option):
        v = self.get(section, option)
        if v.lower() not in self._boolean_states:
            raise ValueError, 'Not a boolean: %s' % v
        return self._boolean_states[v.lower()]

    def optionxform(self, optionstr):
        return optionstr.lower()

    def has_option(self, section, option):
        """Check for the existence of a given option in a given section."""
        if not section or section == DEFAULTSECT:
            option = self.optionxform(option)
            return option in self.__defaults
        elif section not in self.__sections:
            return 0
        else:
            option = self.optionxform(option)
            return (option in self.__sections[section]
                    or option in self.__defaults)

    def set(self, section, option, value):
        """Set an option."""
        if not section or section == DEFAULTSECT:
            sectdict = self.__defaults
        else:
            try:
                sectdict = self.__sections[section]
            except KeyError:
                raise NoSectionError(section)
        sectdict[self.optionxform(option)] = value

    def write(self, fp):
        """Write an .ini-format representation of the configuration state."""
        if self.__defaults:
            fp.write("[%s]\n" % DEFAULTSECT)
            for (key, value) in self.__defaults.items():
                fp.write("%s = %s\n" % (key, str(value).replace('\n', '\n\t')))
            fp.write("\n")
        for section in self.__sections:
            fp.write("[%s]\n" % section)
            for (key, value) in self.__sections[section].items():
                if key != "__name__":
                    fp.write("%s = %s\n" %
                             (key, str(value).replace('\n', '\n\t')))
            fp.write("\n")

    def remove_option(self, section, option):
        """Remove an option."""
        if not section or section == DEFAULTSECT:
            sectdict = self.__defaults
        else:
            try:
                sectdict = self.__sections[section]
            except KeyError:
                raise NoSectionError(section)
        option = self.optionxform(option)
        existed = option in sectdict
        if existed:
            del sectdict[option]
        return existed

    def remove_section(self, section):
        """Remove a file section."""
        existed = section in self.__sections
        if existed:
            del self.__sections[section]
        return existed

    #
    # Regular expressions for parsing section headers and options.
    #
    SECTCRE = re.compile(
        r'\['                                 # [
        r'(?P<header>[^]]+)'                  # very permissive!
        r'\]'                                 # ]
        )
    OPTCRE = re.compile(
        r'(?P<option>[^:=\s][^:=]*)'          # very permissive!
        r'\s*(?P<vi>[:=])\s*'                 # any number of space/tab,
                                              # followed by separator
                                              # (either : or =), followed
                                              # by any # space/tab
        r'(?P<value>.*)$'                     # everything up to eol
        )

    def __read(self, fp, fpname):
        """Parse a sectioned setup file.

        The sections in setup file contains a title line at the top,
        indicated by a name in square brackets (`[]'), plus key/value
        options lines, indicated by `name: value' format lines.
        Continuation are represented by an embedded newline then
        leading whitespace.  Blank lines, lines beginning with a '#',
        and just about everything else is ignored.
        """
        cursect = None                            # None, or a dictionary
        optname = None
        lineno = 0
        e = None                                  # None, or an exception
        while 1:
            line = fp.readline()
            if not line:
                break
            lineno = lineno + 1
            # comment or blank line?
            if line.strip() == '' or line[0] in '#;':
                continue
            if line.split(None, 1)[0].lower() == 'rem' and line[0] in "rR":
                # no leading whitespace
                continue
            # continuation line?
            if line[0].isspace() and cursect is not None and optname:
                value = line.strip()
                if value:
                    cursect[optname] = "%s\n%s" % (cursect[optname], value)
            # a section header or option header?
            else:
                # is it a section header?
                mo = self.SECTCRE.match(line)
                if mo:
                    sectname = mo.group('header')
                    if sectname in self.__sections:
                        cursect = self.__sections[sectname]
                    elif sectname == DEFAULTSECT:
                        cursect = self.__defaults
                    else:
                        cursect = {'__name__': sectname}
                        self.__sections[sectname] = cursect
                    # So sections can't start with a continuation line
                    optname = None
                # no section header in the file?
                elif cursect is None:
                    raise MissingSectionHeaderError(fpname, lineno, `line`)
                # an option line?
                else:
                    mo = self.OPTCRE.match(line)
                    if mo:
                        optname, vi, optval = mo.group('option', 'vi', 'value')
                        if vi in ('=', ':') and ';' in optval:
                            # ';' is a comment delimiter only if it follows
                            # a spacing character
                            pos = optval.find(';')
                            if pos != -1 and optval[pos-1].isspace():
                                optval = optval[:pos]
                        optval = optval.strip()
                        # allow empty values
                        if optval == '""':
                            optval = ''
                        optname = self.optionxform(optname.rstrip())
                        cursect[optname] = optval
                    else:
                        # a non-fatal parsing error occurred.  set up the
                        # exception but keep going. the exception will be
                        # raised at the end of the file and will contain a
                        # list of all bogus lines
                        if not e:
                            e = ParsingError(fpname)
                        e.append(lineno, `line`)
        # if any parsing errors occurred, raise an exception
        if e:
            raise e