cpython/Lib/dos-8x3/configpa.py

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1997-12-09 12:56:41 -04:00
"""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"
# 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
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`)