CODEWITHSUNDEEP
pythonclassdictionary
kartikeykant18
kartikeykant18

Reputation: 1811

a dict being defined in a python class but outside any method

I was going through the code given here : Confused about classes in Learn Python the Hard Way ex43?

when I found out that a dict is defined in the class Map(object) but not in any method. Here is what I mean :

class Map(object):

    scenes = {
        'central_corridor': CentralCorridor(),
        'laser_weapon_armory': LaserWeaponArmory(),
        'the_bridge': TheBridge(),
        'escape_pod': EscapePod(),
        'death': Death()
    }

    def __init__(self, start_scene):
        self.start_scene = start_scene

    def next_scene(self, scene_name):
        return Map.scenes.get(scene_name)

    def opening_scene(self):
        return self.next_scene(self.start_scene)

Later the dict is used in next_scene method. I did not know that anything can be defined in a class outside a method except docstring. Can you please explain how this dict is being used?

Upvotes: 1

Views: 475

Answers (1)

NPE
NPE

Reputation: 500873

In a nutshell, there exists a single instance of this dictionary. It is called Map.scenes and is shared by all instances of the class.

did not know that anything can be defined in a class outside a method except docstring.

In actual fact, you can put pretty much any executable statement inside class:

class HHGTTG(object):
  print 42

Even def is an executable statement in Python.

Upvotes: 4

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