cpython/Lib/ConfigParser.py

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"""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
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 re
DEFAULTSECT = "DEFAULT"
# 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, 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 MissingSectionHeaderError(Error):
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 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 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, unless the optional
argument `raw' is true.
The section DEFAULT is special.
"""
try:
sectdict = self.__sections[section].copy()
except KeyError:
if section == DEFAULTSECT:
sectdict = {}
else:
raise NoSectionError(section)
d = self.__defaults.copy()
d.update(sectdict)
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, rawval)
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
#
# Regular expressions for parsing section headers and options. Note a
# slight semantic change from the previous version, because of the use
# of \w, _ is allowed in section header names.
__SECTCRE = re.compile(
r'\[' # [
r'(?P<header>[-\w]+)' # `-', `_' or any alphanum
r'\]' # ]
)
__OPTCRE = re.compile(
r'(?P<option>[-.\w]+)' # - . _ alphanum
r'[ \t]*[:=][ \t]*' # 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):
"""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 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 is not None and optname:
value = string.strip(line)
if value:
cursect[optname] = cursect[optname] + '\n ' + 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 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
# no section header in the file?
elif cursect is None:
raise MissingSectionHeaderError(fp.name, lineno, `line`)
# an option line?
else:
mo = self.__OPTCRE.match(line)
if mo:
optname, optval = mo.group('option', 'value')
optname = string.lower(optname)
optval = string.strip(optval)
# allow empty values
if optval == '""':
optval = ''
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(fp.name)
e.append(lineno, `line`)
# if any parsing errors occurred, raise an exception
if e:
raise e