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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
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.
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