"""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
has_option(section, option)
return whether the given section has the given option
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 defined as 0 or
1, only)
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 sys
import string
import re
__all__ = ["NoSectionError","DuplicateSectionError","NoOptionError",
"InterpolationError","InterpolationDepthError","ParsingError",
"MissingSectionHeaderError","ConfigParser",
"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 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 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 opts.has_key('__name__'):
del opts['__name__']
return opts.keys()
def has_option(self, section, option):
"""Return whether the given section has the given option."""
return option in self.options(section)
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 type(filenames) in [type(''), type(u'')]:
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.
"""
try:
sectdict = self.__sections[section].copy()
except KeyError:
if section == DEFAULTSECT:
sectdict = {}
else:
raise NoSectionError(section)
d = self.__defaults.copy()
d.update(sectdict)
# Update with the entry specific variables
if vars:
d.update(vars)
option = self.optionxform(option)
try:
rawval = d[option]
except KeyError:
raise NoOptionError(option, section)
if raw:
return rawval
# do the string interpolation
value = rawval # Make it a pretty variable name
depth = 0
while depth < 10: # Loop through this until it's done
depth = depth + 1
if value.find("%(") >= 0:
try:
value = value % d
except KeyError, key:
raise InterpolationError(key, option, section, rawval)
else:
break
if value.find("%(") >= 0:
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, 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 = int(v)
if val not in (0, 1):
raise ValueError, 'Not a boolean: %s' % v
return val
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 == "DEFAULT":
return self.__defaults.has_key(option)
elif not self.has_section(section):
return 0
else:
option = self.optionxform(option)
return self.__sections[section].has_key(option)
def set(self, section, option, value):
"""Set an option."""
if not section or section == "DEFAULT":
sectdict = self.__defaults
else:
try:
sectdict = self.__sections[section]
except KeyError:
raise NoSectionError(section)
option = self.optionxform(option)
sectdict[option] = value
def write(self, fp):
"""Write an .ini-format representation of the configuration state."""
if self.__defaults:
fp.write("[DEFAULT]\n")
for (key, value) in self.__defaults.items():
fp.write("%s = %s\n" % (key, value))
fp.write("\n")
for section in self.sections():
fp.write("[" + section + "]\n")
sectdict = self.__sections[section]
for (key, value) in sectdict.items():
if key == "__name__":
continue
fp.write("%s = %s\n" % (key, value))
fp.write("\n")
def remove_option(self, section, option):
"""Remove an option."""
if not section or section == "DEFAULT":
sectdict = self.__defaults
else:
try:
sectdict = self.__sections[section]
except KeyError:
raise NoSectionError(section)
option = self.optionxform(option)
existed = sectdict.has_key(option)
if existed:
del sectdict[option]
return existed
def remove_section(self, section):
"""Remove a file section."""
if self.__sections.has_key(section):
del self.__sections[section]
return 1
else:
return 0
#
# 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'\[' # [
r'(?P<header>[^]]+)' # very permissive!
r'\]' # ]
)
OPTCRE = re.compile(
r'(?P<option>[]\-[\w_.*,(){}]+)' # a lot of stuff found by IvL
r'[ \t]*(?P<vi>[:=])[ \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, 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()[0].lower() == 'rem' \
and line[0] in "rR": # no leading whitespace
continue
# continuation line?
if line[0] in ' \t' and cursect is not None and optname:
value = line.strip()
if value:
k = self.optionxform(optname)
cursect[k] = "%s\n%s" % (cursect[k], 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(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 and optval[pos-1] in string.whitespace:
optval = optval[:pos]
optval = optval.strip()
# allow empty values
if optval == '""':
optval = ''
cursect[self.optionxform(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
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