Call method from string

Question

If I have a Python class, and would like to call a function from it depending on a variable, how would I do so? I imagined following could do it:

class CallMe: # Class     def App(): # Method one        ...     def Foo(): # Method two        ...  variable = "App" # Method to call  CallMe.variable() # Calling App() 

But it couldn't. Any other way to do this?

Answer 1

You can do this:

getattr(CallMe, variable)() 

getattr is a builtin method, it returns the value of the named attributed of object. The value in this case is a method object that you can call with ()

Answer 2

You can use getattr, or you can assign bound or unbound methods to the variable. Bound methods are tied to a particular instance of the class, and unbound methods are tied to the class, so you have to pass an instance in as the first parameter.

e.g.

class CallMe:     def App(self):         print "this is App"      def Foo(self):         print "I'm Foo"  obj = CallMe()  # bound method: var = obj.App var()         # prints "this is App"  # unbound method: var = CallMe.Foo var(obj)      # prints "I'm Foo"