Initial revision

intern/python/modules/mcf/utils/dummy.py

@@ -0,0 +1,91 @@
+'''
+Dummy Class, intended as an abstract class for the creation
+of base/builtin classes with slightly altered functionality
+uses _base as the name of an instance of the base datatype,
+mapping all special functions to that name.
+
+>>> from mcf.utils import dummy
+
+>>> j = dummy.Dummy({})
+
+>>> j['this'] = 23
+
+>>> j
+
+{'this': 23}
+
+>>> class example(dummy.Dummy):
+
+... 	def __repr__(self):
+
+... 		return '<example: %s>'%`self._base`
+
+>>> k = example([])
+
+>>> k # uses the __repr__ function
+
+<example: []>
+
+>>> k.append # finds the attribute of the _base
+
+<built-in method append of list object at 501830>
+
+'''
+import types, copy
+
+class Dummy:
+	'Abstract class for slightly altering functionality of objects (including builtins)'
+	def __init__(self, val=None):
+		'Initialisation, should be overridden'
+		if val and type(val)== types.InstanceType and hasattr(val, '_base'):
+			# Dict is used because subclasses often want to override
+			# the setattr function
+			self.__dict__['_base']=copy.copy(val.__dict__['_base'])
+		else:
+			self.__dict__['_base'] = val
+	def __repr__(self):
+		'Return a string representation'
+		return repr(self._base)
+	def __str__(self):
+		'Convert to a string'
+		return str(self._base)
+	def __cmp__(self,other):
+		'Compare to other value'
+		# altered 98.03.17 from if...elif...else statement
+		return cmp(self._base, other)
+	def __getitem__(self, key):
+		'Get an item by index'
+		return self._base[key]
+	def __setitem__(self, key, val):
+		'Set an item by index'
+		self._base[key]=val
+	def __len__(self):
+		'return the length of the self'
+		return len(self._base)
+	def __delitem__(self, key):
+		'remove an item by index'
+		del(self._base[key])
+	def __getslice__(self, i, j):
+		'retrieve a slice by indexes'
+		return self._base[i:j]
+	def __setslice__(self, i, j, val):
+		'set a slice by indexes to values'
+		self._base[i:j]=val
+	def __delslice__(self, i, j):
+		'remove a slice by indexes'
+		del(self._base[i:j])
+	def __nonzero__(self):
+		if self._base:
+			return 1
+		else:
+			return 0
+	def __getattr__(self, attr):
+		'find an attribute when normal lookup fails, will raise a KeyError if missing _base attribute'
+		try:
+			return getattr( self.__dict__['_base'], attr)
+		except (AttributeError, KeyError):
+			try:
+				return self.__dict__['_base'][attr]
+			except (KeyError,TypeError):
+				pass
+		raise AttributeError, attr