PKv¯¸47SäBEGG-INFO/namespace_packages.txtpeak peak.util PKv¯¸4ѧinYYEGG-INFO/PKG-INFOMetadata-Version: 1.0 Name: DecoratorTools Version: 1.0 Summary: Use class and function decorators -- even in Python 2.3! Home-page: http://peak.telecommunity.com/DevCenter/DecoratorTools Author: Phillip J. Eby Author-email: peak@eby-sarna.com License: PSF or ZPL Description: Want to use decorators, but still need to support Python 2.3? Wish you could have class decorators, or decorate arbitrary assignments? Then you need "DecoratorTools". Some quick examples:: # Method decorator example from peak.util.decorators import decorate class Demo1(object): decorate(classmethod) # equivalent to @classmethod def example(cls): print "hello from", cls # Class decorator example from peak.util.decorators import decorate_class def my_class_decorator(): def decorator(cls): print "decorating", cls return cls decorate_class(decorator) class Demo2: my_class_decorator() # "decorating " will be printed when execution gets here Installing DecoratorTools (using ``"easy_install DecoratorTools"`` or ``"setup.py install"``) gives you access to the ``peak.util.decorators`` module. The tools in this module have been bundled for years inside of PEAK, PyProtocols, RuleDispatch, and the zope.interface package, so they have been widely used and tested. (Unit tests are also included, of course.) This standalone version is backward-compatible with the bundled versions, so you can mix and match decorators from this package with those provided by zope.interface, TurboGears, etc. Platform: UNKNOWN PKv¯¸4²éÖ55EGG-INFO/SOURCES.txtREADME.txt setup.py test_decorators.py DecoratorTools.egg-info/PKG-INFO DecoratorTools.egg-info/SOURCES.txt DecoratorTools.egg-info/namespace_packages.txt DecoratorTools.egg-info/top_level.txt ez_setup/README.txt ez_setup/__init__.py peak/__init__.py peak/util/__init__.py peak/util/decorators.py PKv¯¸4†êÁEGG-INFO/top_level.txtpeak PKv¯¸4EGG-INFO/zip-safePK/ ·4‰kÔ<99peak/__init__.py__import__('pkg_resources').declare_namespace(__name__) PKv¯¸4ºÑgéÍÍpeak/__init__.pyc;ò ™rDc@sedƒieƒdS(s pkg_resourcesN(s __import__sdeclare_namespaces__name__(((s&build\bdist.win32\egg\peak\__init__.pys?sPK1Ž¸4[8êžÿ$ÿ$peak/util/decorators.pyfrom types import ClassType, FunctionType import sys __all__ = [ 'decorate_class', 'metaclass_is_decorator', 'metaclass_for_bases', 'frameinfo', 'decorate_assignment', 'decorate', ] def decorate(*decorators): """Use Python 2.4 decorators w/Python 2.3+ Example:: class Foo(object): decorate(classmethod) def something(cls,etc): \"""This is a classmethod\""" You can pass in more than one decorator, and they are applied in the same order that would be used for ``@`` decorators in Python 2.4. This function can be used to write decorator-using code that will work with both Python 2.3 and 2.4 (and up). """ if len(decorators)>1: decorators = list(decorators) decorators.reverse() def callback(frame,k,v,old_locals): for d in decorators: v = d(v) return v return decorate_assignment(callback) def frameinfo(frame): """Return (kind, module, locals, globals) tuple for a frame 'kind' is one of "exec", "module", "class", "function call", or "unknown". """ f_locals = frame.f_locals f_globals = frame.f_globals sameNamespace = f_locals is f_globals hasModule = '__module__' in f_locals hasName = '__name__' in f_globals sameName = hasModule and hasName sameName = sameName and f_globals['__name__']==f_locals['__module__'] module = hasName and sys.modules.get(f_globals['__name__']) or None namespaceIsModule = module and module.__dict__ is f_globals if not namespaceIsModule: # some kind of funky exec kind = "exec" if hasModule and not sameNamespace: kind="class" elif sameNamespace and not hasModule: kind = "module" elif sameName and not sameNamespace: kind = "class" elif not sameNamespace: kind = "function call" else: # How can you have f_locals is f_globals, and have '__module__' set? # This is probably module-level code, but with a '__module__' variable. kind = "unknown" return kind,module,f_locals,f_globals def decorate_class(decorator, depth=2, frame=None): """Set up `decorator` to be passed the containing class upon creation This function is designed to be called by a decorator factory function executed in a class suite. The factory function supplies a decorator that it wishes to have executed when the containing class is created. The decorator will be given one argument: the newly created containing class. The return value of the decorator will be used in place of the class, so the decorator should return the input class if it does not wish to replace it. The optional `depth` argument to this function determines the number of frames between this function and the targeted class suite. `depth` defaults to 2, since this skips the caller's frame. Thus, if you call this function from a function that is called directly in the class suite, the default will be correct, otherwise you will need to determine the correct depth value yourself. Alternately, you can pass in a `frame` argument to explicitly indicate what frame is doing the class definition. This function works by installing a special class factory function in place of the ``__metaclass__`` of the containing class. Therefore, only decorators *after* the last ``__metaclass__`` assignment in the containing class will be executed. Thus, any classes using class decorators should declare their ``__metaclass__`` (if any) *before* specifying any class decorators, to ensure that all class decorators will be applied.""" frame = frame or sys._getframe(depth) kind, module, caller_locals, caller_globals = frameinfo(frame) if kind != "class": raise SyntaxError( "Class decorators may only be used inside a class statement" ) previousMetaclass = caller_locals.get('__metaclass__') defaultMetaclass = caller_globals.get('__metaclass__', ClassType) def advise(name,bases,cdict): if '__metaclass__' in cdict: del cdict['__metaclass__'] if previousMetaclass is None: if bases: # find best metaclass or use global __metaclass__ if no bases meta = metaclass_for_bases(bases) else: meta = defaultMetaclass elif metaclass_is_decorator(previousMetaclass): # special case: we can't compute the "true" metaclass here, # so we need to invoke the previous metaclass and let it # figure it out for us (and apply its own advice in the process) meta = previousMetaclass else: meta = metaclass_for_bases(bases, previousMetaclass) newClass = meta(name,bases,cdict) # this lets the decorator replace the class completely, if it wants to return decorator(newClass) # introspection data only, not used by inner function # Note: these attributes cannot be renamed or it will break compatibility # with zope.interface and any other code that uses this decoration protocol advise.previousMetaclass = previousMetaclass advise.callback = decorator # install the advisor caller_locals['__metaclass__'] = advise def metaclass_is_decorator(ob): """True if 'ob' is a class advisor function""" return isinstance(ob,FunctionType) and hasattr(ob,'previousMetaclass') def metaclass_for_bases(bases, explicit_mc=None): """Determine metaclass from 1+ bases and optional explicit __metaclass__""" meta = [getattr(b,'__class__',type(b)) for b in bases] if explicit_mc is not None: # The explicit metaclass needs to be verified for compatibility # as well, and allowed to resolve the incompatible bases, if any meta.append(explicit_mc) if len(meta)==1: # easy case return meta[0] classes = [c for c in meta if c is not ClassType] candidates = [] for m in classes: for n in classes: if issubclass(n,m) and m is not n: break else: # m has no subclasses in 'classes' if m in candidates: candidates.remove(m) # ensure that we're later in the list candidates.append(m) if not candidates: # they're all "classic" classes return ClassType elif len(candidates)>1: # We could auto-combine, but for now we won't... raise TypeError("Incompatible metatypes",bases) # Just one, return it return candidates[0] def decorate_assignment(callback, depth=2, frame=None): """Invoke 'callback(frame,name,value,old_locals)' on next assign in 'frame' The frame monitored is determined by the 'depth' argument, which gets passed to 'sys._getframe()'. When 'callback' is invoked, 'old_locals' contains a copy of the frame's local variables as they were before the assignment took place, allowing the callback to access the previous value of the assigned variable, if any. The callback's return value will become the new value of the variable. 'name' is the name of the variable being created or modified, and 'value' is its value (the same as 'frame.f_locals[name]'). This function also returns a decorator function for forward-compatibility with Python 2.4 '@' syntax. Note, however, that if the returned decorator is used with Python 2.4 '@' syntax, the callback 'name' argument may be 'None' or incorrect, if the 'value' is not the original function (e.g. when multiple decorators are used). """ frame = frame or sys._getframe(depth) oldtrace = [frame.f_trace] old_locals = frame.f_locals.copy() def tracer(frm,event,arg): if event=='call': # We don't want to trace into any calls if oldtrace[0]: # ...but give the previous tracer a chance to, if it wants return oldtrace[0](frm,event,arg) else: return None try: if frm is frame and event !='exception': # Aha, time to check for an assignment... for k,v in frm.f_locals.items(): if k not in old_locals or old_locals[k] is not v: break else: # No luck, keep tracing return tracer # Got it, fire the callback, then get the heck outta here... frm.f_locals[k] = callback(frm,k,v,old_locals) finally: # Give the previous tracer a chance to run before we return if oldtrace[0]: # And allow it to replace our idea of the "previous" tracer oldtrace[0] = oldtrace[0](frm,event,arg) uninstall() return oldtrace[0] def uninstall(): # Unlink ourselves from the trace chain. frame.f_trace = oldtrace[0] sys.settrace(oldtrace[0]) # Install the trace function frame.f_trace = tracer sys.settrace(tracer) def do_decorate(f): # Python 2.4 '@' compatibility; call the callback uninstall() frame = sys._getframe(1) return callback( frame, getattr(f,'__name__',None), f, frame.f_locals ) return do_decorate PKv¯¸46ƒ·&·&peak/util/decorators.pyc;ò îÔtDc@s}dklZlZdkZddddddgZd„Zd „Zd ed „Zd „Z ed „Z d ed„Z dS((s ClassTypes FunctionTypeNsdecorate_classsmetaclass_is_decoratorsmetaclass_for_basess frameinfosdecorate_assignmentsdecoratecsGtˆƒdjotˆƒ‰ˆiƒn‡d†}t|ƒSdS(sÐUse Python 2.4 decorators w/Python 2.3+ Example:: class Foo(object): decorate(classmethod) def something(cls,etc): """This is a classmethod""" You can pass in more than one decorator, and they are applied in the same order that would be used for ``@`` decorators in Python 2.4. 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