--- /dev/null
+"""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 rfc822.
+
+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
+
+ options(section) -- return list of configuration options for the named
+ section
+
+ read(*filenames) -- read and parse the list of named configuration files
+
+ get(section, option, raw=0) -- 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.
+
+ 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 defined as 0
+ or 1, only)
+"""
+
+import sys
+import string
+import regex
+from types import ListType
+
+
+SECTHEAD_RE = "^\[\([-A-Za-z0-9]*\)\][" + string.whitespace + "]*$"
+secthead_cre = regex.compile(SECTHEAD_RE)
+OPTION_RE = "^\([-A-Za-z0-9.]+\)\(:\|[" + string.whitespace + "]*=\)\(.*\)$"
+option_cre = regex.compile(OPTION_RE)
+
+DEFAULTSECT = "DEFAULT"
+
+
+\f
+# exception classes
+class Error:
+ def __init__(self, msg=''):
+ self.__msg = msg
+ def __repr__(self):
+ return self.__msg
+
+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):
+ Error.__init__(self,
+ "Bad value substitution: sect `%s', opt `%s', ref `%s'"
+ % (section, option, reference))
+ self.reference = reference
+ self.option = option
+ self.section = section
+
+
+\f
+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 self.__sections.has_key(section):
+ 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 self.__sections.has_key(section)
+
+ def options(self, section):
+ try:
+ opts = self.__sections[section].copy()
+ except KeyError:
+ raise NoSectionError(section)
+ opts.update(self.__defaults)
+ return opts.keys()
+
+ def read(self, filenames):
+ """Read and parse a list of filenames."""
+ if type(filenames) is type(''):
+ filenames = [filenames]
+ for file in filenames:
+ try:
+ fp = open(file, 'r')
+ self.__read(fp)
+ except IOError:
+ pass
+
+ def get(self, section, option, raw=0):
+ """Get an option value for a given section.
+
+ All % interpolations are expanded in the return values, based
+ on the defaults passed into the constructor.
+
+ The section DEFAULT is special.
+ """
+ try:
+ d = self.__sections[section].copy()
+ except KeyError:
+ if section == DEFAULTSECT:
+ d = {}
+ else:
+ raise NoSectionError(section)
+ d.update(self.__defaults)
+ option = string.lower(option)
+ try:
+ rawval = d[option]
+ except KeyError:
+ raise NoOptionError(option, section)
+ # do the string interpolation
+ if raw:
+ return rawval
+ try:
+ return rawval % d
+ except KeyError, key:
+ raise InterpolationError(key, option, section)
+
+ def __get(self, section, conv, option):
+ return conv(self.get(section, option))
+
+ def getint(self, section, option):
+ return self.__get(section, string.atoi, option)
+
+ def getfloat(self, section, option):
+ return self.__get(section, string.atof, option)
+
+ def getboolean(self, section, option):
+ v = self.get(section, option)
+ val = string.atoi(v)
+ if val not in (0, 1):
+ raise ValueError, 'Not a boolean: %s' % v
+ return val
+
+ def __read(self, fp):
+ """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
+ while 1:
+ line = fp.readline()
+ if not line:
+ break
+ lineno = lineno + 1
+ # comment or blank line?
+ if string.strip(line) == '' or line[0] in '#;':
+ continue
+ if string.lower(string.split(line)[0]) == 'rem' \
+ and line[0] == "r": # no leading whitespace
+ continue
+ # continuation line?
+ if line[0] in ' \t' and cursect <> None and optname:
+ value = string.strip(line)
+ if value:
+ cursect = cursect[optname] + '\n ' + value
+ # a section header?
+ elif secthead_cre.match(line) >= 0:
+ sectname = secthead_cre.group(1)
+ if self.__sections.has_key(sectname):
+ 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
+ # an option line?
+ elif option_cre.match(line) >= 0:
+ optname, optval = option_cre.group(1, 3)
+ optname = string.lower(optname)
+ optval = string.strip(optval)
+ # allow empty values
+ if optval == '""':
+ optval = ''
+ cursect[optname] = optval
+ # an error
+ else:
+ print 'Error in %s at %d: %s', (fp.name, lineno, `line`)
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