pythonの組み込み型に見られる特徴

gistfile1.py

>>> a.__dict__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'int' object has no attribute '__dict__'
>>> a = 10
>>> a.__dict__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'int' object has no attribute '__dict__'
>>> a = 1.0
>>> a.__dict__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'float' object has no attribute '__dict__'
>>> a = "a"
>>> a.__dict__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'str' object has no attribute '__dict__'
>>> a = True
>>> a.__dict__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'bool' object has no attribute '__dict__'
>>> class A(object):
...     pass
... 
>>> a = A()
>>> a.__dict__
{}