Python: Reference to a class from a string?

Question

How to use a string containing a class name to reference a class itself?
See this (not working) exemple...

class WrapperClass:
    def display_var(self):         


        

Answer 1

Depending on where you get this string, any general method may be insecure (one such method is to simply use eval(string). The best method is to define a dict mapping names to classes:

class WrapperClass:
    def display_var(self):
        #FIXME: self.__class_name__.__name__ is a string
        print d[self.__class__.__name__].the_var

class SomeSubClass(WrapperClass):
    the_var = "abc"

class AnotherSubClass(WrapperClass):
    the_var = "def"

d = {'WrapperClass': WrapperClass, 'SomeSubClass': SomeSubClass, 'AnotherSubClass': AnotherSubClass}
AnotherSubClass().display_var()
# prints 'def'