Question

Why is the output different for the following logical operations that I tried in python?

-1 or 1
 1 or -1

First returns -1 and second returns 1

Answer 1

and and or are both lazy; they evaluate operands until they can decide the result (and stops at the first False operand; or stops at the first True operand). They return the last operand evaluated, as noted in the documentation:

Note that neither and nor or restrict the value and type they return to False and True, but rather return the last evaluated argument. This is sometimes useful, e.g., if s is a string that should be replaced by a default value if it is empty, the expression s or 'foo' yields the desired value.