diff options
Diffstat (limited to 'Demo/metaclasses/Enum.py')
| -rw-r--r-- | Demo/metaclasses/Enum.py | 144 |
1 files changed, 72 insertions, 72 deletions
diff --git a/Demo/metaclasses/Enum.py b/Demo/metaclasses/Enum.py index e1ae695..13a3ed7 100644 --- a/Demo/metaclasses/Enum.py +++ b/Demo/metaclasses/Enum.py @@ -12,9 +12,9 @@ class EnumMetaClass: To define your own enumeration, do something like class Color(Enum): - red = 1 - green = 2 - blue = 3 + red = 1 + green = 2 + blue = 3 Now, Color.red, Color.green and Color.blue behave totally different: they are enumerated values, not integers. @@ -25,66 +25,66 @@ class EnumMetaClass: """ def __init__(self, name, bases, dict): - """Constructor -- create an enumeration. - - Called at the end of the class statement. The arguments are - the name of the new class, a tuple containing the base - classes, and a dictionary containing everything that was - entered in the class' namespace during execution of the class - statement. In the above example, it would be {'red': 1, - 'green': 2, 'blue': 3}. - - """ - for base in bases: - if base.__class__ is not EnumMetaClass: - raise TypeError, "Enumeration base class must be enumeration" - bases = filter(lambda x: x is not Enum, bases) - self.__name__ = name - self.__bases__ = bases - self.__dict = {} - for key, value in dict.items(): - self.__dict[key] = EnumInstance(name, key, value) + """Constructor -- create an enumeration. + + Called at the end of the class statement. The arguments are + the name of the new class, a tuple containing the base + classes, and a dictionary containing everything that was + entered in the class' namespace during execution of the class + statement. In the above example, it would be {'red': 1, + 'green': 2, 'blue': 3}. + + """ + for base in bases: + if base.__class__ is not EnumMetaClass: + raise TypeError, "Enumeration base class must be enumeration" + bases = filter(lambda x: x is not Enum, bases) + self.__name__ = name + self.__bases__ = bases + self.__dict = {} + for key, value in dict.items(): + self.__dict[key] = EnumInstance(name, key, value) def __getattr__(self, name): - """Return an enumeration value. + """Return an enumeration value. - For example, Color.red returns the value corresponding to red. + For example, Color.red returns the value corresponding to red. - XXX Perhaps the values should be created in the constructor? + XXX Perhaps the values should be created in the constructor? - This looks in the class dictionary and if it is not found - there asks the base classes. + This looks in the class dictionary and if it is not found + there asks the base classes. - The special attribute __members__ returns the list of names - defined in this class (it does not merge in the names defined - in base classes). + The special attribute __members__ returns the list of names + defined in this class (it does not merge in the names defined + in base classes). - """ - if name == '__members__': - return self.__dict.keys() + """ + if name == '__members__': + return self.__dict.keys() - try: - return self.__dict[name] - except KeyError: - for base in self.__bases__: - try: - return getattr(base, name) - except AttributeError: - continue + try: + return self.__dict[name] + except KeyError: + for base in self.__bases__: + try: + return getattr(base, name) + except AttributeError: + continue - raise AttributeError, name + raise AttributeError, name def __repr__(self): - s = self.__name__ - if self.__bases__: - s = s + '(' + string.join(map(lambda x: x.__name__, - self.__bases__), ", ") + ')' - if self.__dict: - list = [] - for key, value in self.__dict.items(): - list.append("%s: %s" % (key, int(value))) - s = "%s: {%s}" % (s, string.join(list, ", ")) - return s + s = self.__name__ + if self.__bases__: + s = s + '(' + string.join(map(lambda x: x.__name__, + self.__bases__), ", ") + ')' + if self.__dict: + list = [] + for key, value in self.__dict.items(): + list.append("%s: %s" % (key, int(value))) + s = "%s: {%s}" % (s, string.join(list, ", ")) + return s class EnumInstance: @@ -99,23 +99,23 @@ class EnumInstance: """ def __init__(self, classname, enumname, value): - self.__classname = classname - self.__enumname = enumname - self.__value = value + self.__classname = classname + self.__enumname = enumname + self.__value = value def __int__(self): - return self.__value + return self.__value def __repr__(self): - return "EnumInstance(%s, %s, %s)" % (`self.__classname`, - `self.__enumname`, - `self.__value`) + return "EnumInstance(%s, %s, %s)" % (`self.__classname`, + `self.__enumname`, + `self.__value`) def __str__(self): - return "%s.%s" % (self.__classname, self.__enumname) + return "%s.%s" % (self.__classname, self.__enumname) def __cmp__(self, other): - return cmp(self.__value, int(other)) + return cmp(self.__value, int(other)) # Create the base class for enumerations. @@ -126,9 +126,9 @@ Enum = EnumMetaClass("Enum", (), {}) def _test(): class Color(Enum): - red = 1 - green = 2 - blue = 3 + red = 1 + green = 2 + blue = 3 print Color.red print dir(Color) @@ -139,11 +139,11 @@ def _test(): print Color.red == 2 class ExtendedColor(Color): - white = 0 - orange = 4 - yellow = 5 - purple = 6 - black = 7 + white = 0 + orange = 4 + yellow = 5 + purple = 6 + black = 7 print ExtendedColor.orange print ExtendedColor.red @@ -151,11 +151,11 @@ def _test(): print Color.red == ExtendedColor.red class OtherColor(Enum): - white = 4 - blue = 5 + white = 4 + blue = 5 class MergedColor(Color, OtherColor): - pass + pass print MergedColor.red print MergedColor.white |