What is the property of unary plus and minus operators in python?

Question

Unary plus represented as +@ and unary
minus as -@.

How do they differ from conventional (mathematical) + and -.

Answer 1

You can use both versions for example for incrementing a variable:

num *= 2
num = num * 2

If you take a look at the byte code, you can see that 2 differnt methods of calculation are applied:

2 0 LOAD_FAST 0 (x)
2 LOAD_CONST 1 (2)
4 INPLACE_MULTIPLY <<<<<
6 STORE_FAST 0 (x)

3 8 LOAD_FAST 0 (x)
10 RETURN_VALUE
**********
2 0 LOAD_FAST 0 (x)
2 LOAD_CONST 1 (2)
4 BINARY_MULTIPLY <<<<<
6 STORE_FAST 0 (x)

3 8 LOAD_FAST 0 (x)
10 RETURN_VALUE
**********
so first version uses an INPLACE_MULTIPLY, the second version uses a BINARY_MULTIPLY. I dont know the difference.
Execution time has to be checked separately.