Python ID () function decryption process

>>> A = 2.5
>>> B = 2.5
>>> C = B
>>> A is C
False

>>> A = 2
>>> B = 2
>>> C = B
>>> A is C
True

When I use the is function today, I print the numbers A and B are assigned 2.5 and 2 respectively. I found that:
>>> A = 2
>>> B = 2
>>> ID ()
21132060
>>> ID (B)
21132060
>>> A = 2.5
>>> B = 2.5
>>> ID ()
19622112
>>> ID (B)
29321464

When A and B are 2, the ID is the same, but 2.5 is different. This problem also occurs when the string is short, when B is assigned a very short string, their IDs are the same, but long strings do not;
Then, we can get a simple conclusion: the interpreter makes a small Optimization for int and short strings with a small value, and only allocates one object, let them have the same ID.