Square bracket and dot notations?

[Asen Bozhilov]

Hi all,
I am beginner in Python. What is interesting for me is that Python
interpreter treats in different way dot and square bracket notations.
I am coming from JavaScript where both notations lead prototype chain
lookup.

In Python it seems square bracket and dot notations lead lookup in
different "store".

Simple example with dict object:

d = {"key" : "value"}

print d["key"] #value

print d.key #AttributeError

I found an implementation of dict which uses both notations for its
keys lookup, which I think is stupid idea when obviously both
notations lead different lookup. It will confuse me as a reader of the
code.

Anyway, I would like to know more about the lookup for key of dict and
lookup for property of any object with dot notation. Any materials and
explanations are highly appreciated.