JezK
Edit File: ConfigParser.py
"""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 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; its 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. Return list of successfully read files. 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=False, 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 False, and 1, true, yes, on for True). Returns False or True. items(section, raw=False, vars=None) return a list of tuples with (name, value) for each option in the section. 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 """ try: from collections import OrderedDict as _default_dict except ImportError: # fallback for setup.py which hasn't yet built _collections _default_dict = dict import re __all__ = ["NoSectionError", "DuplicateSectionError", "NoOptionError", "InterpolationError", "InterpolationDepthError", "InterpolationSyntaxError", "ParsingError", "MissingSectionHeaderError", "ConfigParser", "SafeConfigParser", "RawConfigParser", "DEFAULTSECT", "MAX_INTERPOLATION_DEPTH"] DEFAULTSECT = "DEFAULT" MAX_INTERPOLATION_DEPTH = 10 # exception classes class Error(Exception): """Base class for ConfigParser exceptions.""" def _get_message(self): """Getter for 'message'; needed only to override deprecation in BaseException.""" return self.__message def _set_message(self, value): """Setter for 'message'; needed only to override deprecation in BaseException.""" self.__message = value # BaseException.message has been deprecated since Python 2.6. To prevent # DeprecationWarning from popping up over this pre-existing attribute, use # a new property that takes lookup precedence. message = property(_get_message, _set_message) def __init__(self, msg=''): self.message = msg Exception.__init__(self, msg) def __repr__(self): return self.message __str__ = __repr__ class NoSectionError(Error): """Raised when no section matches a requested option.""" def __init__(self, section): Error.__init__(self, 'No section: %r' % (section,)) self.section = section self.args = (section, ) class DuplicateSectionError(Error): """Raised when a section is multiply-created.""" def __init__(self, section): Error.__init__(self, "Section %r already exists" % section) self.section = section self.args = (section, ) class NoOptionError(Error): """A requested option was not found.""" def __init__(self, option, section): Error.__init__(self, "No option %r in section: %r" % (option, section)) self.option = option self.section = section self.args = (option, section) class InterpolationError(Error): """Base class for interpolation-related exceptions.""" def __init__(self, option, section, msg): Error.__init__(self, msg) self.option = option self.section = section self.args = (option, section, msg) class InterpolationMissingOptionError(InterpolationError): """A string substitution required a setting which was not available.""" def __init__(self, option, section, rawval, reference): msg = ("Bad value substitution:\n" "\tsection: [%s]\n" "\toption : %s\n" "\tkey : %s\n" "\trawval : %s\n" % (section, option, reference, rawval)) InterpolationError.__init__(self, option, section, msg) self.reference = reference self.args = (option, section, rawval, reference) class InterpolationSyntaxError(InterpolationError): """Raised when the source text into which substitutions are made does not conform to the required syntax.""" class InterpolationDepthError(InterpolationError): """Raised when substitutions are nested too deeply.""" def __init__(self, option, section, rawval): msg = ("Value interpolation too deeply recursive:\n" "\tsection: [%s]\n" "\toption : %s\n" "\trawval : %s\n" % (section, option, rawval)) InterpolationError.__init__(self, option, section, msg) self.args = (option, section, rawval) class ParsingError(Error): """Raised when a configuration file does not follow legal syntax.""" def __init__(self, filename): Error.__init__(self, 'File contains parsing errors: %s' % filename) self.filename = filename self.errors = [] self.args = (filename, ) def append(self, lineno, line): self.errors.append((lineno, line)) self.message += '\n\t[line %2d]: %s' % (lineno, line) class MissingSectionHeaderError(ParsingError): """Raised when a key-value pair is found before any section header.""" def __init__(self, filename, lineno, line): Error.__init__( self, 'File contains no section headers.\nfile: %s, line: %d\n%r' % (filename, lineno, line)) self.filename = filename self.lineno = lineno self.line = line self.args = (filename, lineno, line) class RawConfigParser: def __init__(self, defaults=None, dict_type=_default_dict, allow_no_value=False): self._dict = dict_type self._sections = self._dict() self._defaults = self._dict() if allow_no_value: self._optcre = self.OPTCRE_NV else: self._optcre = self.OPTCRE if defaults: for key, value in defaults.items(): self._defaults[self.optionxform(key)] = value 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. Raise ValueError if name is DEFAULT or any of it's case-insensitive variants. """ if section.lower() == "default": raise ValueError, 'Invalid section name: %s' % section if section in self._sections: raise DuplicateSectionError(section) self._sections[section] = self._dict() 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. Return list of successfully read files. """ if isinstance(filenames, basestring): filenames = [filenames] read_ok = [] for filename in filenames: try: fp = open(filename) except IOError: continue self._read(fp, filename) fp.close() read_ok.append(filename) return read_ok 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): opt = self.optionxform(option) if section not in self._sections: if section != DEFAULTSECT: raise NoSectionError(section) if opt in self._defaults: return self._defaults[opt] else: raise NoOptionError(option, section) elif opt in self._sections[section]: return self._sections[section][opt] elif opt in self._defaults: return self._defaults[opt] else: raise NoOptionError(option, section) def items(self, section): try: d2 = self._sections[section] except KeyError: if section != DEFAULTSECT: raise NoSectionError(section) d2 = self._dict() d = self._defaults.copy() d.update(d2) if "__name__" in d: del d["__name__"] return d.items() 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 False else: option = self.optionxform(option) return (option in self._sections[section] or option in self._defaults) def set(self, section, option, value=None): """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__": continue if (value is not None) or (self._optcre == self.OPTCRE): key = " = ".join((key, str(value).replace('\n', '\n\t'))) fp.write("%s\n" % (key)) 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>.*)$' # everything up to eol ) OPTCRE_NV = re.compile( r'(?P<option>[^:=\s][^:=]*)' # very permissive! r'\s*(?:' # any number of space/tab, r'(?P<vi>[:=])\s*' # optionally followed by # separator (either : or # =), followed by any # # space/tab r'(?P<value>.*))?$' # 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. Continuations are represented by an embedded newline then leading whitespace. Blank lines, lines beginning with a '#', and just about everything else are ignored. """ cursect = None # None, or a dictionary optname = None lineno = 0 e = None # None, or an exception while True: 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].append(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 = self._dict() 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') optname = self.optionxform(optname.rstrip()) # This check is fine because the OPTCRE cannot # match if it would set optval to None if optval is not None: 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 = '' cursect[optname] = [optval] else: # valueless option handling 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, repr(line)) # if any parsing errors occurred, raise an exception if e: raise e # join the multi-line values collected while reading all_sections = [self._defaults] all_sections.extend(self._sections.values()) for options in all_sections: for name, val in options.items(): if isinstance(val, list): options[name] = '\n'.join(val) import UserDict as _UserDict class _Chainmap(_UserDict.DictMixin): """Combine multiple mappings for successive lookups. For example, to emulate Python's normal lookup sequence: import __builtin__ pylookup = _Chainmap(locals(), globals(), vars(__builtin__)) """ def __init__(self, *maps): self._maps = maps def __getitem__(self, key): for mapping in self._maps: try: return mapping[key] except KeyError: pass raise KeyError(key) def keys(self): result = [] seen = set() for mapping in self._maps: for key in mapping: if key not in seen: result.append(key) seen.add(key) return result class ConfigParser(RawConfigParser): def get(self, section, option, raw=False, vars=None): """Get an option value for a given section. If `vars' is provided, it must be a dictionary. The option is looked up in `vars' (if provided), `section', and in `defaults' in that order. All % interpolations are expanded in the return values, unless the optional argument `raw' is true. Values for interpolation keys are looked up in the same manner as the option. The section DEFAULT is special. """ sectiondict = {} try: sectiondict = self._sections[section] except KeyError: if section != DEFAULTSECT: raise NoSectionError(section) # Update with the entry specific variables vardict = {} if vars: for key, value in vars.items(): vardict[self.optionxform(key)] = value d = _Chainmap(vardict, sectiondict, self._defaults) option = self.optionxform(option) try: value = d[option] except KeyError: raise NoOptionError(option, section) if raw or value is None: return value else: return self._interpolate(section, option, value, d) def items(self, section, raw=False, vars=None): """Return a list of tuples with (name, value) for each option in the 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: for key, value in vars.items(): d[self.optionxform(key)] = value options = d.keys() if "__name__" in options: options.remove("__name__") if raw: return [(option, d[option]) for option in options] else: return [(option, self._interpolate(section, option, d[option], d)) for option in options] 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 and "%(" in value: value = self._KEYCRE.sub(self._interpolation_replace, value) try: value = value % vars except KeyError, e: raise InterpolationMissingOptionError( option, section, rawval, e.args[0]) else: break if value and "%(" in value: raise InterpolationDepthError(option, section, rawval) return value _KEYCRE = re.compile(r"%\(([^)]*)\)s|.") def _interpolation_replace(self, match): s = match.group(1) if s is None: return match.group() else: return "%%(%s)s" % self.optionxform(s) class SafeConfigParser(ConfigParser): def _interpolate(self, section, option, rawval, vars): # do the string interpolation L = [] self._interpolate_some(option, L, rawval, section, vars, 1) return ''.join(L) _interpvar_re = re.compile(r"%\(([^)]+)\)s") def _interpolate_some(self, option, accum, rest, section, map, depth): if depth > MAX_INTERPOLATION_DEPTH: raise InterpolationDepthError(option, section, rest) while rest: p = rest.find("%") if p < 0: accum.append(rest) return if p > 0: accum.append(rest[:p]) rest = rest[p:] # p is no longer used c = rest[1:2] if c == "%": accum.append("%") rest = rest[2:] elif c == "(": m = self._interpvar_re.match(rest) if m is None: raise InterpolationSyntaxError(option, section, "bad interpolation variable reference %r" % rest) var = self.optionxform(m.group(1)) rest = rest[m.end():] try: v = map[var] except KeyError: raise InterpolationMissingOptionError( option, section, rest, var) if "%" in v: self._interpolate_some(option, accum, v, section, map, depth + 1) else: accum.append(v) else: raise InterpolationSyntaxError( option, section, "'%%' must be followed by '%%' or '(', found: %r" % (rest,)) def set(self, section, option, value=None): """Set an option. Extend ConfigParser.set: check for string values.""" # The only legal non-string value if we allow valueless # options is None, so we need to check if the value is a # string if: # - we do not allow valueless options, or # - we allow valueless options but the value is not None if self._optcre is self.OPTCRE or value: if not isinstance(value, basestring): raise TypeError("option values must be strings") if value is not None: # check for bad percent signs: # first, replace all "good" interpolations tmp_value = value.replace('%%', '') tmp_value = self._interpvar_re.sub('', tmp_value) # then, check if there's a lone percent sign left if '%' in tmp_value: raise ValueError("invalid interpolation syntax in %r at " "position %d" % (value, tmp_value.find('%'))) ConfigParser.set(self, section, option, value)