dir() does much more than look up __dict__ First of all, dir() is a API method that knows how to use attributes like __dict__ to look up attributes of an object. Not all objects have a __dict__ attribute though. For example, if you were to add a __slots__ attribute to your custom class, instances of … Read more
A little nicer than inspecting the code object directly and working out the variables is to use the inspect module. >>> import inspect >>> def func(a,b,c=42, *args, **kwargs): pass >>> inspect.getargspec(func) ([‘a’, ‘b’, ‘c’], ‘args’, ‘kwargs’, (42,)) If you want to know if its callable with a particular set of args, you need the args … Read more
The proper Swift operator is is: if touch.view is UIPickerView { // touch.view is of type UIPickerView } Of course, if you also need to assign the view to a new constant, then the if let … as? … syntax is your boy, as Kevin mentioned. But if you don’t need the value and only … Read more
inspect.getmro(cls) works for both new and old style classes and returns the same as NewClass.mro(): a list of the class and all its ancestor classes, in the order used for method resolution. >>> class A(object): >>> pass >>> >>> class B(A): >>> pass >>> >>> import inspect >>> inspect.getmro(B) (<class ‘__main__.B’>, <class ‘__main__.A’>, <type ‘object’>)
The stack frame tells us what code object we’re in. If we can find a function object that refers to that code object in its __code__ attribute, we have found the function. Fortunately, we can ask the garbage collector which objects hold a reference to our code object, and sift through those, rather than having … Read more
Well, for one, the Swift equivalent of [NSString class] is .self (see Metatype docs, though they’re pretty thin). In fact, NSString.class doesn’t even work! You have to use NSString.self. let s = NSString.self var str = s() str = “asdf” Similarly, with a swift class I tried… class MyClass { } let MyClassRef = MyClass.self … Read more
Use the built-in function dir().
kind_of? and is_a? are synonymous. instance_of? is different from the other two in that it only returns true if the object is an instance of that exact class, not a subclass. Example: “hello”.is_a? Object and “hello”.kind_of? Object return true because “hello” is a String and String is a subclass of Object. However “hello”.instance_of? Object returns … Read more
_meta is private, but it’s relatively stable. There are efforts to formalise it, document it and remove the underscore, which might happen before 1.3 or 1.4. I imagine effort will be made to ensure things are backwards compatible, because lots of people have been using it anyway. If you’re particularly concerned about compatibility, write a … Read more
Check out the inspect module: inspect.stack() will return the stack information. Inside a function, inspect.stack()[1] will return your caller’s stack. From there, you can get more information about the caller’s function name, module, etc. See the docs for details: http://docs.python.org/library/inspect.html Also, Doug Hellmann has a nice writeup of the inspect module in his PyMOTW series: … Read more