introspection

Consider two classes. The first is Vehicle , an NSObject subclass that conforms to NSCopying : class Vehicle : NSObject, NSCopying { var wheels = 4 func copyWithZone(zone: NSZone) -> AnyObject { let vehicle = self.dynamicType() vehicle.wheels = self.wheels return vehicle } } The second class, Starship , inherits from Vehicle : class Starship : Vehicle { var photonTorpedos = 6 var antiGravity = true override func copyWithZone(zone: NSZone) -> AnyObject { let starship = super.copyWithZone(zone) as Starship starship.photonTorpedos = self.photonTorpedos starship.antiGravity = self.antiGravity

How do I check if an object is an instance of a Named tuple ? Alex Martelli Calling the function collections.namedtuple gives you a new type that's a subclass of tuple (and no other classes) with a member named _fields that's a tuple whose items are all strings. So you could check for each and every one of these things: def isnamedtupleinstance(x): t = type(x) b = t.__bases__ if len(b) != 1 or b[0] != tuple: return False f = getattr(t, '_fields', None) if not isinstance(f, tuple): return False return all(type(n)==str for n in f) it IS possible to get a false positive from this, but only if

Given a class C in Python, how can I determine which file the class was defined in? I need something that can work from either the class C, or from an instance off C. The reason I am doing this, is because I am generally a fan off putting files that belong together in the same folder. I want to create a class that uses a Django template to render itself as HTML. The base implementation should infer the filename for the template based on the filename that the class is defined in. Say I put a class LocationArtifact in the file "base/artifacts.py", then I want the default behaviour to be that the

In Objective-C I can test whether a given class or instance responds to certain selectors. But how can query a class or instance for all its methods or properties of a class (e.g. a list of all methods or properties)? Ben Gottlieb You'll want to use the Objective C runtime methods, see here: https://developer.apple.com/reference/objectivec/objective_c_runtime You can do this and it is extremely well documented at https://developer.apple.com/library/mac/documentation/cocoa/Reference/ObjCRuntimeRef/index.html To fetch all the instance or class methods of a class, you may use class_copyMethodList

I am trying to obtain class information on a field inside a model, when I only know name of the field and name of the model (both plain strings). How is it possible? I can load the model dynamically: from django.db import models model = models.get_model('myapp','mymodel') Now I have field - 'myfield' - how can I get the class of that field? If the field is relational - how to get related field? Thanks a bunch! Anurag Uniyal You can use model's _meta attribute to get field object and from field you can get relationship and much more e.g. consider a employee table which has a foreign key to a