Can set any property of Python object

Question

For example, this code is Python:

a = object()
a.b = 3

throws AttributeError: \'object\' object has no attribute \'b\'

Answer 1

This happens because when you say a.b = 3, it creates a variable in a that represents b. For example,

class a: pass
print a.b

returns AttributeError: class a has no attribute b

However this code,

class a: pass
a.b = 3
print a.b

returns 3 as it sets the value of b in a, to 3.