yaml.load does not call __init__ of objects

[aymanbahrain@…]

I noticed that my init code is not called when an object is created via yaml.load. Try this one: In this example, fy.secret will raise an error about secret not an attribute of fy object.

import yaml

class Field:
    def __init__(self):
        print 'init called'
        self.secret = 'password'
        
f = Field()

print f.secret

fy = yaml.load(file('fld.yaml', 'r'))
print fy.hide_value               
print fy.secret

have fld.yaml contain:
!!python/object:__main__.Field 
hide_value: true

[xi]

PyYAML implements the pickle protocol for serializing and deserializing class instances. That is, yaml.load(yaml.dump(instance)) is supposed to work exactly like pickle.loads(pickle.dumps(instance)). The __init__ method is never called by pickle. If you want to customize object creation, you may define a __setstate__ method instead.

For more information on the pickle protocol, check  http://www.python.org/dev/peps/pep-0307/.