class surgery

>>> class Foo(object):
...     def __init__(self, x):
...             self.x = x
...     def spam(self):
...             print('spam')
... 
>>> f = Foo(2)
>>> f.x
2
>>> f.spam()
spam
>>> 

>>> name = 'Foo'
>>> bases = (object, )
>>> def __init__(self, x):
...     self.x = x
... 
>>> def spam(self):
...     print('spam')
... 
>>> methods = {'__init__': __init__, 'spam': spam}
>>> 
>>> name
'Foo'
>>> bases
(<class 'object'>,)
>>> methods
{'__init__': <function __init__ at 0x7f95b61b0598>, 'spam': <function spam at 0x7f95b61b0730>}
>>> Foo = type(name, bases, methods)
>>> Foo
<class '__main__.Foo'>
>>> f = Foo(2)
>>> f.x
2
>>> f.spam()
spam