id(object)
This is an integer (or long integer) which is guaranteed to be unique and constant for this object during its lifetime.
Can you explain this output? Why does j's id change?
>>> i=10 >>> id(i) 6337824 >>> j=10 >>> id(j) 6337824 >>> j=j+1 >>> id(j) 6337800 >>> id(i) 6337824 