python create object from string

Question

I have the next situation. The goal of the following method is to return the object created from the incoming string. So I have:

class Situation(Generator):
         


        

Answer 1

You can easily map strings to classes, yes. Classes are just more objects, you can store them in other Python objects.

You can manually build a dictionary mapping strings to classes:

classes = {'situation': Situation}

You can automate this a little by creating a class decorator, perhaps:

classes = {}
def register(cls):
    classes[cls.__name__.lower()] = cls
    return cls

@register
class Situation(Generator):
    # ...

Each class you prefix with @register will be added to the dictionary, with the class name lowercased as the key.

or you can use the globals() function to get a dictionary of all globals in your module. The latter is a little... overkill and also a security hazard, you could end up giving end-users way more access than you bargained for, as that also gives them other classes and functions you didn't mean to expose.

Once you have a dictionary, just access the right class and call it:

class Generator(object):
    def createsituation(self, stringsituation="situation"):
        return classes[stringsituation]()