python under the hood

[tpochep at mail.ru]

Hello.

Is there any good information about python's internals and semantic? I
mean "under the hood".
For example, I want to understant what do these strings

x = 10
y = 10
x = 20

mean (memory allocation for object? ctors? etc.)
Unfortynatly, I'm too lazy to read python's source code :) (and I
guess, it's not very easy :) )