--- /dev/null
+#!/usr/bin/env python
+#-*- coding:utf-8 -*-
+
+
+
+# Copyright 2004-2007 by Vinay Sajip. All Rights Reserved.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose and without fee is hereby granted,
+# provided that the above copyright notice appear in all copies and that
+# both that copyright notice and this permission notice appear in
+# supporting documentation, and that the name of Vinay Sajip
+# not be used in advertising or publicity pertaining to distribution
+# of the software without specific, written prior permission.
+# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
+# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
+# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""
+This is a configuration module for Python.
+
+This module should work under Python versions >= 2.2, and cannot be used with
+earlier versions since it uses new-style classes.
+
+Development and testing has only been carried out (so far) on Python 2.3.4 and
+Python 2.4.2. See the test module (test_config.py) included in the
+U{distribution<http://www.red-dove.com/python_config.html|_blank>} (follow the
+download link).
+
+A simple example - with the example configuration file::
+
+ messages:
+ [
+ {
+ stream : `sys.stderr`
+ message: 'Welcome'
+ name: 'Harry'
+ }
+ {
+ stream : `sys.stdout`
+ message: 'Welkom'
+ name: 'Ruud'
+ }
+ {
+ stream : $messages[0].stream
+ message: 'Bienvenue'
+ name: Yves
+ }
+ ]
+
+a program to read the configuration would be::
+
+ from config import Config
+
+ f = file('simple.cfg')
+ cfg = Config(f)
+ for m in cfg.messages:
+ s = '%s, %s' % (m.message, m.name)
+ try:
+ print >> m.stream, s
+ except IOError, e:
+ print e
+
+which, when run, would yield the console output::
+
+ Welcome, Harry
+ Welkom, Ruud
+ Bienvenue, Yves
+
+See U{this tutorial<http://www.red-dove.com/python_config.html|_blank>} for more
+information.
+
+#modified for salomeTools
+@version: 0.3.7.1
+
+@author: Vinay Sajip
+
+@copyright: Copyright (C) 2004-2007 Vinay Sajip. All Rights Reserved.
+
+
+@var streamOpener: The default stream opener. This is a factory function which
+takes a string (e.g. filename) and returns a stream suitable for reading. If
+unable to open the stream, an IOError exception should be thrown.
+
+The default value of this variable is L{defaultStreamOpener}. For an example
+of how it's used, see test_config.py (search for streamOpener).
+"""
+
+__author__ = "Vinay Sajip <vinay_sajip@red-dove.com>"
+__status__ = "alpha"
+__version__ = "0.3.7.1" #modified for salomeTools
+__date__ = "05 October 2007"
+
+import codecs
+import os
+import sys
+
+WORD = 'a'
+NUMBER = '9'
+STRING = '"'
+EOF = ''
+LCURLY = '{'
+RCURLY = '}'
+LBRACK = '['
+LBRACK2 = 'a['
+RBRACK = ']'
+LPAREN = '('
+LPAREN2 = '(('
+RPAREN = ')'
+DOT = '.'
+COMMA = ','
+COLON = ':'
+AT = '@'
+PLUS = '+'
+MINUS = '-'
+STAR = '*'
+SLASH = '/'
+MOD = '%'
+BACKTICK = '`'
+DOLLAR = '$'
+TRUE = 'True'
+FALSE = 'False'
+NONE = 'None'
+
+WORDCHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_"
+
+if sys.platform == 'win32':
+ NEWLINE = '\r\n'
+elif os.name == 'mac':
+ NEWLINE = '\r'
+else:
+ NEWLINE = '\n'
+
+try:
+ has_utf32 = True
+except:
+ has_utf32 = False
+
+class ConfigInputStream(object):
+ """
+ An input stream which can read either ANSI files with default encoding
+ or Unicode files with BOMs.
+
+ Handles UTF-8, UTF-16LE, UTF-16BE. Could handle UTF-32 if Python had
+ built-in support.
+ """
+ def __init__(self, stream):
+ """
+ Initialize an instance.
+
+ @param stream: The underlying stream to be read. Should be seekable.
+ @type stream: A stream (file-like object).
+ """
+ encoding = None
+ signature = stream.read(4)
+ used = -1
+ if has_utf32:
+ if signature == codecs.BOM_UTF32_LE:
+ encoding = 'utf-32le'
+ elif signature == codecs.BOM_UTF32_BE:
+ encoding = 'utf-32be'
+ if encoding is None:
+ if signature[:3] == codecs.BOM_UTF8:
+ used = 3
+ encoding = 'utf-8'
+ elif signature[:2] == codecs.BOM_UTF16_LE:
+ used = 2
+ encoding = 'utf-16le'
+ elif signature[:2] == codecs.BOM_UTF16_BE:
+ used = 2
+ encoding = 'utf-16be'
+ else:
+ used = 0
+ if used >= 0:
+ stream.seek(used)
+ if encoding:
+ reader = codecs.getreader(encoding)
+ stream = reader(stream)
+ self.stream = stream
+ self.encoding = encoding
+
+ def read(self, size):
+ if (size == 0) or (self.encoding is None):
+ rv = self.stream.read(size)
+ else:
+ rv = u''
+ while size > 0:
+ rv += self.stream.read(1)
+ size -= 1
+ return rv
+
+ def close(self):
+ self.stream.close()
+
+ def readline(self):
+ if self.encoding is None:
+ line = ''
+ else:
+ line = u''
+ while True:
+ c = self.stream.read(1)
+ if isinstance(c, bytes):
+ c = c.decode()
+ if c:
+ line += c
+ if c == '\n':
+ break
+ return line
+
+class ConfigOutputStream(object):
+ """
+ An output stream which can write either ANSI files with default encoding
+ or Unicode files with BOMs.
+
+ Handles UTF-8, UTF-16LE, UTF-16BE. Could handle UTF-32 if Python had
+ built-in support.
+ """
+
+ def __init__(self, stream, encoding=None):
+ """
+ Initialize an instance.
+
+ @param stream: The underlying stream to be written.
+ @type stream: A stream (file-like object).
+ @param encoding: The desired encoding.
+ @type encoding: str
+ """
+ if encoding is not None:
+ encoding = str(encoding).lower()
+ self.encoding = encoding
+ if encoding == "utf-8":
+ stream.write(codecs.BOM_UTF8)
+ elif encoding == "utf-16be":
+ stream.write(codecs.BOM_UTF16_BE)
+ elif encoding == "utf-16le":
+ stream.write(codecs.BOM_UTF16_LE)
+ elif encoding == "utf-32be":
+ stream.write(codecs.BOM_UTF32_BE)
+ elif encoding == "utf-32le":
+ stream.write(codecs.BOM_UTF32_LE)
+
+ if encoding is not None:
+ writer = codecs.getwriter(encoding)
+ stream = writer(stream)
+ self.stream = stream
+
+ def write(self, data):
+ self.stream.write(data)
+
+ def flush(self):
+ self.stream.flush()
+
+ def close(self):
+ self.stream.close()
+
+def defaultStreamOpener(name):
+ """
+ This function returns a read-only stream, given its name. The name passed
+ in should correspond to an existing stream, otherwise an exception will be
+ raised.
+
+ This is the default value of L{streamOpener}; assign your own callable to
+ streamOpener to return streams based on names. For example, you could use
+ urllib2.urlopen().
+
+ @param name: The name of a stream, most commonly a file name.
+ @type name: str
+ @return: A stream with the specified name.
+ @rtype: A read-only stream (file-like object)
+ """
+ return ConfigInputStream(open(name, 'rb'))
+
+streamOpener = None
+
+__resolveOverwrite__ = True
+
+class ConfigError(Exception):
+ """
+ This is the base class of exceptions raised by this module.
+ """
+ pass
+
+class ConfigFormatError(ConfigError):
+ """
+ This is the base class of exceptions raised due to syntax errors in
+ configurations.
+ """
+ pass
+
+class ConfigResolutionError(ConfigError):
+ """
+ This is the base class of exceptions raised due to semantic errors in
+ configurations.
+ """
+ pass
+
+def isWord(s):
+ """
+ See if a passed-in value is an identifier. If the value passed in is not a
+ string, False is returned. An identifier consists of alphanumerics or
+ underscore characters.
+
+ Examples::
+
+ isWord('a word') ->False
+ isWord('award') -> True
+ isWord(9) -> False
+ isWord('a_b_c_') ->True
+
+ @note: isWord('9abc') will return True - not exactly correct, but adequate
+ for the way it's used here.
+
+ @param s: The name to be tested
+ @type s: any
+ @return: True if a word, else False
+ @rtype: bool
+ """
+ if type(s) != type(''):
+ return False
+ s = s.replace('_', '')
+ return s.isalnum()
+
+def makePath(prefix, suffix):
+ """
+ Make a path from a prefix and suffix.
+
+ Examples::
+
+ makePath('', 'suffix') -> 'suffix'
+ makePath('prefix', 'suffix') -> 'prefix.suffix'
+ makePath('prefix', '[1]') -> 'prefix[1]'
+
+ @param prefix: The prefix to use. If it evaluates as false, the suffix
+ is returned.
+ @type prefix: str
+ @param suffix: The suffix to use. It is either an identifier or an
+ index in brackets.
+ @type suffix: str
+ @return: The path concatenation of prefix and suffix, with a
+ dot if the suffix is not a bracketed index.
+ @rtype: str
+
+ """
+ if not prefix:
+ rv = suffix
+ elif suffix[0] == '[':
+ rv = prefix + suffix
+ else:
+ rv = prefix + '.' + suffix
+ return rv
+
+
+class Container(object):
+ """
+ This internal class is the base class for mappings and sequences.
+
+ @ivar path: A string which describes how to get
+ to this instance from the root of the hierarchy.
+
+ Example::
+
+ a.list.of[1].or['more'].elements
+ """
+ def __init__(self, parent):
+ """
+ Initialize an instance.
+
+ @param parent: The parent of this instance in the hierarchy.
+ @type parent: A L{Container} instance.
+ """
+ object.__setattr__(self, 'parent', parent)
+
+ def setPath(self, path):
+ """
+ Set the path for this instance.
+ @param path: The path - a string which describes how to get
+ to this instance from the root of the hierarchy.
+ @type path: str
+ """
+ object.__setattr__(self, 'path', path)
+
+ def evaluate(self, item):
+ """
+ Evaluate items which are instances of L{Reference} or L{Expression}.
+
+ L{Reference} instances are evaluated using L{Reference.resolve},
+ and L{Expression} instances are evaluated using
+ L{Expression.evaluate}.
+
+ @param item: The item to be evaluated.
+ @type item: any
+ @return: If the item is an instance of L{Reference} or L{Expression},
+ the evaluated value is returned, otherwise the item is returned
+ unchanged.
+ """
+ if isinstance(item, Reference):
+ item = item.resolve(self)
+ elif isinstance(item, Expression):
+ item = item.evaluate(self)
+ return item
+
+ def writeToStream(self, stream, indent, container):
+ """
+ Write this instance to a stream at the specified indentation level.
+
+ Should be redefined in subclasses.
+
+ @param stream: The stream to write to
+ @type stream: A writable stream (file-like object)
+ @param indent: The indentation level
+ @type indent: int
+ @param container: The container of this instance
+ @type container: L{Container}
+ @raise NotImplementedError: If a subclass does not override this
+ """
+ raise NotImplementedError
+
+ def writeValue(self, value, stream, indent):
+ if isinstance(self, Mapping):
+ indstr = ' '
+ else:
+ indstr = indent * ' '
+ if isinstance(value, Reference) or isinstance(value, Expression):
+ stream.write('%s%r%s' % (indstr, value, NEWLINE))
+ else:
+ if isinstance(value, str): # and not isWord(value):
+ value = repr(value)
+ stream.write('%s%s%s' % (indstr, value, NEWLINE))
+
+class Mapping(Container):
+ """
+ This internal class implements key-value mappings in configurations.
+ """
+
+ def __init__(self, parent=None):
+ """
+ Initialize an instance.
+
+ @param parent: The parent of this instance in the hierarchy.
+ @type parent: A L{Container} instance.
+ """
+ Container.__init__(self, parent)
+ object.__setattr__(self, 'path', '')
+ object.__setattr__(self, 'data', {})
+ object.__setattr__(self, 'order', []) # to preserve ordering
+ object.__setattr__(self, 'comments', {})
+
+ def __delitem__(self, key):
+ """
+ Remove an item
+ """
+ data = object.__getattribute__(self, 'data')
+ if key not in data:
+ raise AttributeError(key)
+ order = object.__getattribute__(self, 'order')
+ comments = object.__getattribute__(self, 'comments')
+ del data[key]
+ order.remove(key)
+ del comments[key]
+
+ def __getitem__(self, key):
+ data = object.__getattribute__(self, 'data')
+ if key not in data:
+ raise AttributeError(key)
+ rv = data[key]
+ return self.evaluate(rv)
+
+ __getattr__ = __getitem__
+
+ '''
+ def __getattribute__(self, name):
+ if name == "__dict__":
+ return {}
+ if name in ["__methods__", "__members__"]:
+ return []
+ #if name == "__class__":
+ # return ''
+ data = object.__getattribute__(self, "data")
+ useData = data.has_key(name)
+ if useData:
+ rv = getattr(data, name)
+ else:
+ rv = object.__getattribute__(self, name)
+ if rv is None:
+ raise AttributeError(name)
+ return rv
+ '''
+
+ def iteritems(self):
+ for key in self.keys():
+ yield(key, self[key])
+ raise StopIteration
+
+ def __contains__(self, item):
+ order = object.__getattribute__(self, 'order')
+ return item in order
+
+ def addMapping(self, key, value, comment, setting=False):
+ """
+ Add a key-value mapping with a comment.
+
+ @param key: The key for the mapping.
+ @type key: str
+ @param value: The value for the mapping.
+ @type value: any
+ @param comment: The comment for the key (can be None).
+ @type comment: str
+ @param setting: If True, ignore clashes. This is set
+ to true when called from L{__setattr__}.
+ @raise ConfigFormatError: If an existing key is seen
+ again and setting is False.
+ """
+ data = object.__getattribute__(self, 'data')
+ order = object.__getattribute__(self, 'order')
+ comments = object.__getattribute__(self, 'comments')
+
+ data[key] = value
+ if key not in order:
+ order.append(key)
+ elif not setting:
+ raise ConfigFormatError("repeated key: %s" % key)
+ comments[key] = comment
+
+ def __setattr__(self, name, value):
+ self.addMapping(name, value, None, True)
+
+ __setitem__ = __setattr__
+
+ def keys(self):
+ """
+ Return the keys in a similar way to a dictionary.
+ """
+ return object.__getattribute__(self, 'order')
+
+ def get(self, key, default=None):
+ """
+ Allows a dictionary-style get operation.
+ """
+ if key in self:
+ return self[key]
+ return default
+
+ def __str__(self):
+ return str(object.__getattribute__(self, 'data'))
+
+ def __repr__(self):
+ return repr(object.__getattribute__(self, 'data'))
+
+ def __len__(self):
+ return len(object.__getattribute__(self, 'order'))
+
+ def __iter__(self):
+ return self.iterkeys()
+
+ def iterkeys(self):
+ order = object.__getattribute__(self, 'order')
+ return order.__iter__()
+
+ def writeToStream(self, stream, indent, container):
+ """
+ Write this instance to a stream at the specified indentation level.
+
+ Should be redefined in subclasses.
+
+ @param stream: The stream to write to
+ @type stream: A writable stream (file-like object)
+ @param indent: The indentation level
+ @type indent: int
+ @param container: The container of this instance
+ @type container: L{Container}
+ """
+ indstr = indent * ' '
+ if len(self) == 0:
+ stream.write(' { }%s' % NEWLINE)
+ else:
+ if isinstance(container, Mapping):
+ stream.write(NEWLINE)
+ stream.write('%s{%s' % (indstr, NEWLINE))
+ self.__save__(stream, indent + 1)
+ stream.write('%s}%s' % (indstr, NEWLINE))
+
+ def __save__(self, stream, indent=0):
+ """
+ Save this configuration to the specified stream.
+ @param stream: A stream to which the configuration is written.
+ @type stream: A write-only stream (file-like object).
+ @param indent: The indentation level for the output.
+ @type indent: int
+ """
+ indstr = indent * ' '
+ order = object.__getattribute__(self, 'order')
+ data = object.__getattribute__(self, 'data')
+ maxlen = 0 # max(map(lambda x: len(x), order))
+ for key in order:
+ comment = self.comments[key]
+ if isWord(key):
+ skey = key
+ else:
+ skey = repr(key)
+ if comment:
+ stream.write('%s#%s' % (indstr, comment))
+ stream.write('%s%-*s :' % (indstr, maxlen, skey))
+ value = data[key]
+ if isinstance(value, Container):
+ value.writeToStream(stream, indent, self)
+ else:
+ self.writeValue(value, stream, indent)
+
+class Config(Mapping):
+ """
+ This class represents a configuration, and is the only one which clients
+ need to interface to, under normal circumstances.
+ """
+
+ class Namespace(object):
+ """
+ This internal class is used for implementing default namespaces.
+
+ An instance acts as a namespace.
+ """
+ def __init__(self):
+ self.sys = sys
+ self.os = os
+
+ def __init__(self, streamOrFile=None, parent=None):
+ """
+ Initializes an instance.
+
+ @param streamOrFile: If specified, causes this instance to be loaded
+ from the stream (by calling L{load}). If a string is provided, it is
+ passed to L{streamOpener} to open a stream. Otherwise, the passed
+ value is assumed to be a stream and used as is.
+ @type streamOrFile: A readable stream (file-like object) or a name.
+ @param parent: If specified, this becomes the parent of this instance
+ in the configuration hierarchy.
+ @type parent: a L{Container} instance.
+ """
+ Mapping.__init__(self, parent)
+ object.__setattr__(self, 'reader', ConfigReader(self))
+ object.__setattr__(self, 'namespaces', [Config.Namespace()])
+ if streamOrFile is not None:
+ if isinstance(streamOrFile, str) or isinstance(streamOrFile, unicode):
+ global streamOpener
+ if streamOpener is None:
+ streamOpener = defaultStreamOpener
+ streamOrFile = streamOpener(streamOrFile)
+ load = object.__getattribute__(self, "load")
+ load(streamOrFile)
+
+ def load(self, stream):
+ """
+ Load the configuration from the specified stream. Multiple streams can
+ be used to populate the same instance, as long as there are no
+ clashing keys. The stream is closed.
+ @param stream: A stream from which the configuration is read.
+ @type stream: A read-only stream (file-like object).
+ @raise ConfigError: if keys in the loaded configuration clash with
+ existing keys.
+ @raise ConfigFormatError: if there is a syntax error in the stream.
+ """
+ reader = object.__getattribute__(self, 'reader')
+ reader.load(stream)
+ stream.close()
+
+ def addNamespace(self, ns, name=None):
+ """
+ Add a namespace to this configuration which can be used to evaluate
+ (resolve) dotted-identifier expressions.
+ @param ns: The namespace to be added.
+ @type ns: A module or other namespace suitable for passing as an
+ argument to vars().
+ @param name: A name for the namespace, which, if specified, provides
+ an additional level of indirection.
+ @type name: str
+ """
+ namespaces = object.__getattribute__(self, 'namespaces')
+ if name is None:
+ namespaces.append(ns)
+ else:
+ setattr(namespaces[0], name, ns)
+
+ def removeNamespace(self, ns, name=None):
+ """
+ Remove a namespace added with L{addNamespace}.
+ @param ns: The namespace to be removed.
+ @param name: The name which was specified when L{addNamespace} was
+ called.
+ @type name: str
+ """
+ namespaces = object.__getattribute__(self, 'namespaces')
+ if name is None:
+ namespaces.remove(ns)
+ else:
+ delattr(namespaces[0], name)
+
+ def __save__(self, stream, indent=0, no_close=False):
+ """
+ Save this configuration to the specified stream. The stream is
+ closed if this is the top-level configuration in the hierarchy.
+ L{Mapping.__save__} is called to do all the work.
+ @param stream: A stream to which the configuration is written.
+ @type stream: A write-only stream (file-like object).
+ @param indent: The indentation level for the output.
+ @type indent: int
+ """
+ Mapping.__save__(self, stream, indent)
+ if indent == 0 and not no_close:
+ stream.close()
+
+ def getByPath(self, path):
+ """
+ Obtain a value in the configuration via its path.
+ @param path: The path of the required value
+ @type path: str
+ @return the value at the specified path.
+ @rtype: any
+ @raise ConfigError: If the path is invalid
+ """
+ s = 'self.' + path
+ try:
+ return eval(s)
+ except Exception as e:
+ raise ConfigError(str(e))
+
+class Sequence(Container):
+ """
+ This internal class implements a value which is a sequence of other values.
+ """
+ class SeqIter(object):
+ """
+ This internal class implements an iterator for a L{Sequence} instance.
+ """
+ def __init__(self, seq):
+ self.seq = seq
+ self.limit = len(object.__getattribute__(seq, 'data'))
+ self.index = 0
+
+ def __iter__(self):
+ return self
+
+ def next(self):
+ if self.index >= self.limit:
+ raise StopIteration
+ rv = self.seq[self.index]
+ self.index += 1
+ return rv
+
+ def __init__(self, parent=None):
+ """
+ Initialize an instance.
+
+ @param parent: The parent of this instance in the hierarchy.
+ @type parent: A L{Container} instance.
+ """
+ Container.__init__(self, parent)
+ object.__setattr__(self, 'data', [])
+ object.__setattr__(self, 'comments', [])
+
+ def append(self, item, comment):
+ """
+ Add an item to the sequence.
+
+ @param item: The item to add.
+ @type item: any
+ @param comment: A comment for the item.
+ @type comment: str
+ """
+ data = object.__getattribute__(self, 'data')
+ comments = object.__getattribute__(self, 'comments')
+ data.append(item)
+ comments.append(comment)
+
+ def __getitem__(self, index):
+ data = object.__getattribute__(self, 'data')
+ try:
+ rv = data[index]
+ except (IndexError, KeyError, TypeError):
+ raise ConfigResolutionError('%r is not a valid index for %r' % (index, object.__getattribute__(self, 'path')))
+ if not isinstance(rv, list):
+ rv = self.evaluate(rv)
+ else:
+ # deal with a slice
+ result = []
+ for a in rv:
+ result.append(self.evaluate(a))
+ rv = result
+ return rv
+
+ def __iter__(self):
+ return Sequence.SeqIter(self)
+
+ def __repr__(self):
+ return repr(object.__getattribute__(self, 'data'))
+
+ def __str__(self):
+ return str(self[:]) # using the slice evaluates the contents
+
+ def __len__(self):
+ return len(object.__getattribute__(self, 'data'))
+
+ def writeToStream(self, stream, indent, container):
+ """
+ Write this instance to a stream at the specified indentation level.
+
+ Should be redefined in subclasses.
+
+ @param stream: The stream to write to
+ @type stream: A writable stream (file-like object)
+ @param indent: The indentation level
+ @type indent: int
+ @param container: The container of this instance
+ @type container: L{Container}
+ """
+ indstr = indent * ' '
+ if len(self) == 0:
+ stream.write(' [ ]%s' % NEWLINE)
+ else:
+ if isinstance(container, Mapping):
+ stream.write(NEWLINE)
+ stream.write('%s[%s' % (indstr, NEWLINE))
+ self.__save__(stream, indent + 1)
+ stream.write('%s]%s' % (indstr, NEWLINE))
+
+ def __save__(self, stream, indent):
+ """
+ Save this instance to the specified stream.
+ @param stream: A stream to which the configuration is written.
+ @type stream: A write-only stream (file-like object).
+ @param indent: The indentation level for the output, > 0
+ @type indent: int
+ """
+ if indent == 0:
+ raise ConfigError("sequence cannot be saved as a top-level item")
+ data = object.__getattribute__(self, 'data')
+ comments = object.__getattribute__(self, 'comments')
+ indstr = indent * ' '
+ for i in xrange(0, len(data)):
+ value = data[i]
+ comment = comments[i]
+ if comment:
+ stream.write('%s#%s' % (indstr, comment))
+ if isinstance(value, Container):
+ value.writeToStream(stream, indent, self)
+ else:
+ self.writeValue(value, stream, indent)
+
+class Reference(object):
+ """
+ This internal class implements a value which is a reference to another value.
+ """
+ def __init__(self, config, type, ident):
+ """
+ Initialize an instance.
+
+ @param config: The configuration which contains this reference.
+ @type config: A L{Config} instance.
+ @param type: The type of reference.
+ @type type: BACKTICK or DOLLAR
+ @param ident: The identifier which starts the reference.
+ @type ident: str
+ """
+ self.config = config
+ self.type = type
+ self.elements = [ident]
+
+ def addElement(self, type, ident):
+ """
+ Add an element to the reference.
+
+ @param type: The type of reference.
+ @type type: BACKTICK or DOLLAR
+ @param ident: The identifier which continues the reference.
+ @type ident: str
+ """
+ self.elements.append((type, ident))
+
+ def findConfig(self, container):
+ """
+ Find the closest enclosing configuration to the specified container.
+
+ @param container: The container to start from.
+ @type container: L{Container}
+ @return: The closest enclosing configuration, or None.
+ @rtype: L{Config}
+ """
+ while (container is not None) and not isinstance(container, Config):
+ container = object.__getattribute__(container, 'parent')
+ return container
+
+ def resolve(self, container):
+ """
+ Resolve this instance in the context of a container.
+
+ @param container: The container to resolve from.
+ @type container: L{Container}
+ @return: The resolved value.
+ @rtype: any
+ @raise ConfigResolutionError: If resolution fails.
+ """
+ rv = None
+ path = object.__getattribute__(container, 'path')
+ current = container
+ while current is not None:
+ if self.type == BACKTICK:
+ namespaces = object.__getattribute__(current, 'namespaces')
+ found = False
+ for ns in namespaces:
+ try:
+ rv = eval(str(self)[1:-1], vars(ns))
+ found = True
+ break
+ except:
+ pass
+ if found:
+ break
+ else:
+ key = self.elements[0]
+ try:
+ rv = current[key]
+ for item in self.elements[1:]:
+ key = item[1]
+ rv = rv[key]
+ break
+ except:
+ rv = None
+ pass
+ current = object.__getattribute__(current, 'parent')
+ if current is None:
+ raise ConfigResolutionError("unable to evaluate %r in the configuration %s" % (self, path))
+ return rv
+
+ def __str__(self):
+ s = self.elements[0]
+ for tt, tv in self.elements[1:]:
+ if tt == DOT:
+ s += '.%s' % tv
+ else:
+ s += '[%r]' % tv
+ if self.type == BACKTICK:
+ return BACKTICK + s + BACKTICK
+ else:
+ return DOLLAR + s
+
+ def __repr__(self):
+ return self.__str__()
+
+class Expression(object):
+ """
+ This internal class implements a value which is obtained by evaluating an expression.
+ """
+ def __init__(self, op, lhs, rhs):
+ """
+ Initialize an instance.
+
+ @param op: the operation expressed in the expression.
+ @type op: PLUS, MINUS, STAR, SLASH, MOD
+ @param lhs: the left-hand-side operand of the expression.
+ @type lhs: any Expression or primary value.
+ @param rhs: the right-hand-side operand of the expression.
+ @type rhs: any Expression or primary value.
+ """
+ self.op = op
+ self.lhs = lhs
+ self.rhs = rhs
+
+ def __str__(self):
+ return '%r %s %r' % (self.lhs, self.op, self.rhs)
+
+ def __repr__(self):
+ return self.__str__()
+
+ def evaluate(self, container):
+ """
+ Evaluate this instance in the context of a container.
+
+ @param container: The container to evaluate in from.
+ @type container: L{Container}
+ @return: The evaluated value.
+ @rtype: any
+ @raise ConfigResolutionError: If evaluation fails.
+ @raise ZeroDivideError: If division by zero occurs.
+ @raise TypeError: If the operation is invalid, e.g.
+ subtracting one string from another.
+ """
+ lhs = self.lhs
+ if isinstance(lhs, Reference):
+ lhs = lhs.resolve(container)
+ elif isinstance(lhs, Expression):
+ lhs = lhs.evaluate(container)
+ rhs = self.rhs
+ if isinstance(rhs, Reference):
+ rhs = rhs.resolve(container)
+ elif isinstance(rhs, Expression):
+ rhs = rhs.evaluate(container)
+ op = self.op
+ if op == PLUS:
+ rv = lhs + rhs
+ elif op == MINUS:
+ rv = lhs - rhs
+ elif op == STAR:
+ rv = lhs * rhs
+ elif op == SLASH:
+ rv = lhs / rhs
+ else:
+ rv = lhs % rhs
+ return rv
+
+class ConfigReader(object):
+ """
+ This internal class implements a parser for configurations.
+ """
+
+ def __init__(self, config):
+ self.filename = None
+ self.config = config
+ self.lineno = 0
+ self.colno = 0
+ self.lastc = None
+ self.last_token = None
+ self.commentchars = '#'
+ self.whitespace = ' \t\r\n'
+ self.quotes = '\'"'
+ self.punct = ':-+*/%,.{}[]()@`$'
+ self.digits = '0123456789'
+ self.wordchars = '%s' % WORDCHARS # make a copy
+ self.identchars = self.wordchars + self.digits
+ self.pbchars = []
+ self.pbtokens = []
+ self.comment = None
+
+ def location(self):
+ """
+ Return the current location (filename, line, column) in the stream
+ as a string.
+
+ Used when printing error messages,
+
+ @return: A string representing a location in the stream being read.
+ @rtype: str
+ """
+ return "%s(%d,%d)" % (self.filename, self.lineno, self.colno)
+
+ def getChar(self):
+ """
+ Get the next char from the stream. Update line and column numbers
+ appropriately.
+
+ @return: The next character from the stream.
+ @rtype: str
+ """
+ if self.pbchars:
+ c = self.pbchars.pop()
+ if isinstance(c,bytes):
+ c = c.decode()
+ else:
+ c = self.stream.read(1)
+ if isinstance(c,bytes):
+ c = c.decode()
+ self.colno += 1
+ if c == '\n':
+ self.lineno += 1
+ self.colno = 1
+ return c
+
+ def __repr__(self):
+ return "<ConfigReader at 0x%08x>" % id(self)
+
+ __str__ = __repr__
+
+ def getToken(self):
+ """
+ Get a token from the stream. String values are returned in a form
+ where you need to eval() the returned value to get the actual
+ string. The return value is (token_type, token_value).
+
+ Multiline string tokenizing is thanks to David Janes (BlogMatrix)
+
+ @return: The next token.
+ @rtype: A token tuple.
+ """
+ if self.pbtokens:
+ return self.pbtokens.pop()
+ stream = self.stream
+ self.comment = None
+ token = ''
+ tt = EOF
+ while True:
+ c = self.getChar()
+ if not c:
+ break
+ elif c == '#':
+ if self.comment :
+ self.comment += '#' + stream.readline()
+ else :
+ self.comment = stream.readline()
+ self.lineno += 1
+ continue
+ if c in self.quotes:
+ token = c
+ quote = c
+ tt = STRING
+ escaped = False
+ multiline = False
+ c1 = self.getChar()
+ if c1 == quote:
+ c2 = self.getChar()
+ if c2 == quote:
+ multiline = True
+ token += quote
+ token += quote
+ else:
+ self.pbchars.append(c2)
+ self.pbchars.append(c1)
+ else:
+ self.pbchars.append(c1)
+ while True:
+ c = self.getChar()
+ if not c:
+ break
+ token += c
+ if (c == quote) and not escaped:
+ if not multiline or (len(token) >= 6 and token.endswith(token[:3]) and token[-4] != '\\'):
+ break
+ if c == '\\':
+ escaped = not escaped
+ else:
+ escaped = False
+ if not c:
+ raise ConfigFormatError('%s: Unterminated quoted string: %r, %r' % (self.location(), token, c))
+ break
+ if c in self.whitespace:
+ self.lastc = c
+ continue
+ elif c in self.punct:
+ token = c
+ tt = c
+ if (self.lastc == ']') or (self.lastc in self.identchars):
+ if c == '[':
+ tt = LBRACK2
+ elif c == '(':
+ tt = LPAREN2
+ break
+ elif c in self.digits:
+ token = c
+ tt = NUMBER
+ while True:
+ c = self.getChar()
+ if not c:
+ break
+ if c in self.digits:
+ token += c
+ elif (c == '.') and token.find('.') < 0:
+ token += c
+ else:
+ if c and (c not in self.whitespace):
+ self.pbchars.append(c)
+ break
+ break
+ elif c in self.wordchars:
+ token = c
+ tt = WORD
+ c = self.getChar()
+ while c and (c in self.identchars):
+ token += c
+ c = self.getChar()
+ if c: # and c not in self.whitespace:
+ self.pbchars.append(c)
+ if token == "True":
+ tt = TRUE
+ elif token == "False":
+ tt = FALSE
+ elif token == "None":
+ tt = NONE
+ break
+ else:
+ raise ConfigFormatError('%s: Unexpected character: %r' % (self.location(), c))
+ if token:
+ self.lastc = token[-1]
+ else:
+ self.lastc = None
+ self.last_token = tt
+ return (tt, token)
+
+ def load(self, stream, parent=None, suffix=None):
+ """
+ Load the configuration from the specified stream.
+
+ @param stream: A stream from which to load the configuration.
+ @type stream: A stream (file-like object).
+ @param parent: The parent of the configuration (to which this reader
+ belongs) in the hierarchy. Specified when the configuration is
+ included in another one.
+ @type parent: A L{Container} instance.
+ @param suffix: The suffix of this configuration in the parent
+ configuration. Should be specified whenever the parent is not None.
+ @raise ConfigError: If parent is specified but suffix is not.
+ @raise ConfigFormatError: If there are syntax errors in the stream.
+ """
+ if parent is not None:
+ if suffix is None:
+ raise ConfigError("internal error: load called with parent but no suffix")
+ self.config.setPath(makePath(object.__getattribute__(parent, 'path'), suffix))
+ self.setStream(stream)
+ self.token = self.getToken()
+ self.parseMappingBody(self.config)
+ if self.token[0] != EOF:
+ raise ConfigFormatError('%s: expecting EOF, found %r' % (self.location(), self.token[1]))
+
+ def setStream(self, stream):
+ """
+ Set the stream to the specified value, and prepare to read from it.
+
+ @param stream: A stream from which to load the configuration.
+ @type stream: A stream (file-like object).
+ """
+ self.stream = stream
+ if hasattr(stream, 'name'):
+ filename = stream.name
+ else:
+ filename = '?'
+ self.filename = filename
+ self.lineno = 1
+ self.colno = 1
+
+ def match(self, t):
+ """
+ Ensure that the current token type matches the specified value, and
+ advance to the next token.
+
+ @param t: The token type to match.
+ @type t: A valid token type.
+ @return: The token which was last read from the stream before this
+ function is called.
+ @rtype: a token tuple - see L{getToken}.
+ @raise ConfigFormatError: If the token does not match what's expected.
+ """
+ if self.token[0] != t:
+ raise ConfigFormatError("%s: expecting %s, found %r" % (self.location(), t, self.token[1]))
+ rv = self.token
+ self.token = self.getToken()
+ return rv
+
+ def parseMappingBody(self, parent):
+ """
+ Parse the internals of a mapping, and add entries to the provided
+ L{Mapping}.
+
+ @param parent: The mapping to add entries to.
+ @type parent: A L{Mapping} instance.
+ """
+ while self.token[0] in [WORD, STRING]:
+ self.parseKeyValuePair(parent)
+
+ def parseKeyValuePair(self, parent):
+ """
+ Parse a key-value pair, and add it to the provided L{Mapping}.
+
+ @param parent: The mapping to add entries to.
+ @type parent: A L{Mapping} instance.
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ comment = self.comment
+ tt, tv = self.token
+ if tt == WORD:
+ key = tv
+ suffix = tv
+ elif tt == STRING:
+ key = eval(tv)
+ suffix = '[%s]' % tv
+ else:
+ msg = "%s: expecting word or string, found %r"
+ raise ConfigFormatError(msg % (self.location(), tv))
+ self.token = self.getToken()
+ # for now, we allow key on its own as a short form of key : True
+ if self.token[0] == COLON:
+ self.token = self.getToken()
+ value = self.parseValue(parent, suffix)
+ else:
+ value = True
+ try:
+ parent.addMapping(key, value, comment)
+ except Exception as e:
+ raise ConfigFormatError("%s: %s, %r" % (self.location(), e,
+ self.token[1]))
+ tt = self.token[0]
+ if tt not in [EOF, WORD, STRING, RCURLY, COMMA]:
+ msg = "%s: expecting one of EOF, WORD, STRING, \
+RCURLY, COMMA, found %r"
+ raise ConfigFormatError(msg % (self.location(), self.token[1]))
+ if tt == COMMA:
+ self.token = self.getToken()
+
+ def parseValue(self, parent, suffix):
+ """
+ Parse a value.
+
+ @param parent: The container to which the value will be added.
+ @type parent: A L{Container} instance.
+ @param suffix: The suffix for the value.
+ @type suffix: str
+ @return: The value
+ @rtype: any
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ tt = self.token[0]
+ if tt in [STRING, WORD, NUMBER, LPAREN, DOLLAR,
+ TRUE, FALSE, NONE, BACKTICK, MINUS]:
+ rv = self.parseScalar()
+ elif tt == LBRACK:
+ rv = self.parseSequence(parent, suffix)
+ elif tt in [LCURLY, AT]:
+ rv = self.parseMapping(parent, suffix)
+ else:
+ raise ConfigFormatError("%s: unexpected input: %r" %
+ (self.location(), self.token[1]))
+ return rv
+
+ def parseSequence(self, parent, suffix):
+ """
+ Parse a sequence.
+
+ @param parent: The container to which the sequence will be added.
+ @type parent: A L{Container} instance.
+ @param suffix: The suffix for the value.
+ @type suffix: str
+ @return: a L{Sequence} instance representing the sequence.
+ @rtype: L{Sequence}
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ rv = Sequence(parent)
+ rv.setPath(makePath(object.__getattribute__(parent, 'path'), suffix))
+ self.match(LBRACK)
+ comment = self.comment
+ tt = self.token[0]
+ while tt in [STRING, WORD, NUMBER, LCURLY, LBRACK, LPAREN, DOLLAR,
+ TRUE, FALSE, NONE, BACKTICK]:
+ suffix = '[%d]' % len(rv)
+ value = self.parseValue(parent, suffix)
+ rv.append(value, comment)
+ tt = self.token[0]
+ comment = self.comment
+ if tt == COMMA:
+ self.match(COMMA)
+ tt = self.token[0]
+ comment = self.comment
+ continue
+ self.match(RBRACK)
+ return rv
+
+ def parseMapping(self, parent, suffix):
+ """
+ Parse a mapping.
+
+ @param parent: The container to which the mapping will be added.
+ @type parent: A L{Container} instance.
+ @param suffix: The suffix for the value.
+ @type suffix: str
+ @return: a L{Mapping} instance representing the mapping.
+ @rtype: L{Mapping}
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ if self.token[0] == LCURLY:
+ self.match(LCURLY)
+ rv = Mapping(parent)
+ rv.setPath(
+ makePath(object.__getattribute__(parent, 'path'), suffix))
+ self.parseMappingBody(rv)
+ self.match(RCURLY)
+ else:
+ self.match(AT)
+ _, fn = self.match(STRING)
+ rv = Config(eval(fn), parent)
+ return rv
+
+ def parseScalar(self):
+ """
+ Parse a scalar - a terminal value such as a string or number, or
+ an L{Expression} or L{Reference}.
+
+ @return: the parsed scalar
+ @rtype: any scalar
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ lhs = self.parseTerm()
+ tt = self.token[0]
+ while tt in [PLUS, MINUS]:
+ self.match(tt)
+ rhs = self.parseTerm()
+ lhs = Expression(tt, lhs, rhs)
+ tt = self.token[0]
+ return lhs
+
+ def parseTerm(self):
+ """
+ Parse a term in an additive expression (a + b, a - b)
+
+ @return: the parsed term
+ @rtype: any scalar
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ lhs = self.parseFactor()
+ tt = self.token[0]
+ while tt in [STAR, SLASH, MOD]:
+ self.match(tt)
+ rhs = self.parseFactor()
+ lhs = Expression(tt, lhs, rhs)
+ tt = self.token[0]
+ return lhs
+
+ def parseFactor(self):
+ """
+ Parse a factor in an multiplicative expression (a * b, a / b, a % b)
+
+ @return: the parsed factor
+ @rtype: any scalar
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ tt = self.token[0]
+ if tt in [NUMBER, WORD, STRING, TRUE, FALSE, NONE]:
+ rv = self.token[1]
+ if tt != WORD:
+ rv = eval(rv)
+ self.match(tt)
+ elif tt == LPAREN:
+ self.match(LPAREN)
+ rv = self.parseScalar()
+ self.match(RPAREN)
+ elif tt == DOLLAR:
+ self.match(DOLLAR)
+ rv = self.parseReference(DOLLAR)
+ elif tt == BACKTICK:
+ self.match(BACKTICK)
+ rv = self.parseReference(BACKTICK)
+ self.match(BACKTICK)
+ elif tt == MINUS:
+ self.match(MINUS)
+ rv = -self.parseScalar()
+ else:
+ raise ConfigFormatError("%s: unexpected input: %r" %
+ (self.location(), self.token[1]))
+ return rv
+
+ def parseReference(self, type):
+ """
+ Parse a reference.
+
+ @return: the parsed reference
+ @rtype: L{Reference}
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ word = self.match(WORD)
+ rv = Reference(self.config, type, word[1])
+ while self.token[0] in [DOT, LBRACK2]:
+ self.parseSuffix(rv)
+ return rv
+
+ def parseSuffix(self, ref):
+ """
+ Parse a reference suffix.
+
+ @param ref: The reference of which this suffix is a part.
+ @type ref: L{Reference}.
+ @raise ConfigFormatError: if a syntax error is found.
+ """
+ tt = self.token[0]
+ if tt == DOT:
+ self.match(DOT)
+ word = self.match(WORD)
+ ref.addElement(DOT, word[1])
+ else:
+ self.match(LBRACK2)
+ tt, tv = self.token
+ if tt not in [NUMBER, STRING]:
+ raise ConfigFormatError("%s: expected number or string, found %r" % (self.location(), tv))
+ self.token = self.getToken()
+ tv = eval(tv)
+ self.match(RBRACK)
+ ref.addElement(LBRACK, tv)
+
+def defaultMergeResolve(map1, map2, key):
+ """
+ A default resolver for merge conflicts. Returns a string
+ indicating what action to take to resolve the conflict.
+
+ @param map1: The map being merged into.
+ @type map1: L{Mapping}.
+ @param map2: The map being used as the merge operand.
+ @type map2: L{Mapping}.
+ @param key: The key in map2 (which also exists in map1).
+ @type key: str
+ @return: One of "merge", "append", "mismatch" or "overwrite"
+ indicating what action should be taken. This should
+ be appropriate to the objects being merged - e.g.
+ there is no point returning "merge" if the two objects
+ are instances of L{Sequence}.
+ @rtype: str
+ """
+ obj1 = map1[key]
+ obj2 = map2[key]
+ if isinstance(obj1, Mapping) and isinstance(obj2, Mapping):
+ rv = "merge"
+ elif isinstance(obj1, Sequence) and isinstance(obj2, Sequence):
+ rv = "append"
+ else:
+ rv = "mismatch"
+ return rv
+
+def overwriteMergeResolve(map1, map2, key):
+ """
+ An overwriting resolver for merge conflicts. Calls L{defaultMergeResolve},
+ but where a "mismatch" is detected, returns "overwrite" instead.
+
+ @param map1: The map being merged into.
+ @type map1: L{Mapping}.
+ @param map2: The map being used as the merge operand.
+ @type map2: L{Mapping}.
+ @param key: The key in map2 (which also exists in map1).
+ @type key: str
+ """
+ rv = defaultMergeResolve(map1, map2, key)
+ if rv == "mismatch":
+ rv = "overwrite"
+ return rv
+
+class ConfigMerger(object):
+ """
+ This class is used for merging two configurations. If a key exists in the
+ merge operand but not the merge target, then the entry is copied from the
+ merge operand to the merge target. If a key exists in both configurations,
+ then a resolver (a callable) is called to decide how to handle the
+ conflict.
+ """
+
+ def __init__(self, resolver=defaultMergeResolve):
+ """
+ Initialise an instance.
+
+ @param resolver:
+ @type resolver: A callable which takes the argument list
+ (map1, map2, key) where map1 is the mapping being merged into,
+ map2 is the merge operand and key is the clashing key. The callable
+ should return a string indicating how the conflict should be resolved.
+ For possible return values, see L{defaultMergeResolve}. The default
+ value preserves the old behaviour
+ """
+ self.resolver = resolver
+
+ def merge(self, merged, mergee):
+ """
+ Merge two configurations. The second configuration is unchanged,
+ and the first is changed to reflect the results of the merge.
+
+ @param merged: The configuration to merge into.
+ @type merged: L{Config}.
+ @param mergee: The configuration to merge.
+ @type mergee: L{Config}.
+ """
+ self.mergeMapping(merged, mergee)
+
+ def overwriteKeys(self, map1, seq2):
+ """
+ Renint variables. The second mapping is unchanged,
+ and the first is changed depending the keys of the second mapping.
+ @param map1: The mapping to reinit keys into.
+ @type map1: L{Mapping}.
+ @param map2: The mapping container reinit information.
+ @type map2: L{Mapping}.
+ """
+
+ overwrite_list = object.__getattribute__(seq2, 'data')
+ for overwrite_instruction in overwrite_list:
+ object.__setattr__(overwrite_instruction, 'parent', map1)
+ if "__condition__" in overwrite_instruction.keys():
+ overwrite_condition = overwrite_instruction["__condition__"]
+ if eval(overwrite_condition, globals(), map1):
+ for key in overwrite_instruction.keys():
+ if key == "__condition__":
+ continue
+ try:
+ exec( 'map1.' + key + " = " + repr(overwrite_instruction[key]))
+ except:
+ exec('map1.' + key + " = " + str(overwrite_instruction[key]))
+ else:
+ for key in overwrite_instruction.keys():
+ try:
+ exec('map1.' + key + " = " + repr(overwrite_instruction[key]))
+ except:
+ exec('map1.' + key + " = " + str(overwrite_instruction[key]))
+
+ def mergeMapping(self, map1, map2):
+ """
+ Merge two mappings recursively. The second mapping is unchanged,
+ and the first is changed to reflect the results of the merge.
+
+ @param map1: The mapping to merge into.
+ @type map1: L{Mapping}.
+ @param map2: The mapping to merge.
+ @type map2: L{Mapping}.
+ """
+ keys = map1.keys()
+ global __resolveOverwrite__
+ for key in map2.keys():
+ if __resolveOverwrite__ and key == "__overwrite__":
+ self.overwriteKeys(map1,map2[key])
+
+ elif key not in keys:
+ map1[key] = map2[key]
+ if isinstance(map1[key], Container) :
+ object.__setattr__(map1[key], 'parent', map1)
+ else:
+ obj1 = map1[key]
+ obj2 = map2[key]
+ decision = self.resolver(map1, map2, key)
+ if decision == "merge":
+ self.mergeMapping(obj1, obj2)
+ elif decision == "append":
+ self.mergeSequence(obj1, obj2)
+ elif decision == "overwrite":
+ map1[key] = obj2
+ if isinstance(map1[key], Container):
+ object.__setattr__(map1[key], 'parent', map1)
+ elif decision == "mismatch":
+ self.handleMismatch(obj1, obj2)
+ else:
+ msg = "unable to merge: don't know how to implement %r"
+ raise ValueError(msg % decision)
+
+ def mergeSequence(self, seq1, seq2):
+ """
+ Merge two sequences. The second sequence is unchanged,
+ and the first is changed to have the elements of the second
+ appended to it.
+
+ @param seq1: The sequence to merge into.
+ @type seq1: L{Sequence}.
+ @param seq2: The sequence to merge.
+ @type seq2: L{Sequence}.
+ """
+ data1 = object.__getattribute__(seq1, 'data')
+ data2 = object.__getattribute__(seq2, 'data')
+ for obj in data2:
+ data1.append(obj)
+ comment1 = object.__getattribute__(seq1, 'comments')
+ comment2 = object.__getattribute__(seq2, 'comments')
+ for obj in comment2:
+ comment1.append(obj)
+
+ def handleMismatch(self, obj1, obj2):
+ """
+ Handle a mismatch between two objects.
+
+ @param obj1: The object to merge into.
+ @type obj1: any
+ @param obj2: The object to merge.
+ @type obj2: any
+ """
+ raise ConfigError("unable to merge %r with %r" % (obj1, obj2))
+
+class ConfigList(list):
+ """
+ This class implements an ordered list of configurations and allows you
+ to try getting the configuration from each entry in turn, returning
+ the first successfully obtained value.
+ """
+
+ def getByPath(self, path):
+ """
+ Obtain a value from the first configuration in the list which defines
+ it.
+
+ @param path: The path of the value to retrieve.
+ @type path: str
+ @return: The value from the earliest configuration in the list which
+ defines it.
+ @rtype: any
+ @raise ConfigError: If no configuration in the list has an entry with
+ the specified path.
+ """
+ found = False
+ rv = None
+ for entry in self:
+ try:
+ rv = entry.getByPath(path)
+ found = True
+ break
+ except ConfigError:
+ pass
+ if not found:
+ raise ConfigError("unable to resolve %r" % path)
+ return rv
