Change operator precedence in Python

Question

I have overloaded some Python operators, arithmetic and boolean. The Python precedence rules remain in effect, which is unnatural for the overloaded operators, leading to lo

Answer 1

You can cheat that mechanism in this way:

1. Override all operators to not do the calculations but create list of instructions wrapped in some object.
2. Add your own bracket operator (ie. as a _ function).

Example:

>>> a = MyNumber(5); b = MyNumber(2); c = MyNumber(3)
>>> a + b * c
MyExpression([MyNumber(5), '+', MyNumber(2), '*', MyNumber(3)])

Brackets:

>>> a + _(b * c)

Note that _ is a function that evaluates expression (in order you enforce in it)

So if you reverse priorites you will get:

>>> _(a + b * c)
MyNumber(21)

PS. Django does similar trick with Q and F operators.

Answer 2

No. It's part of the python language itself. Thats how the language parses.

Official quote: Evaluation order

Python evaluates expressions from left to right. Notice that while evaluating an assignment, the right-hand side is evaluated before the left-hand side.

Other quotes:

Python:Basics:Numbers and operators

When performing mathematical operations with mixed operators, it is important to note that Python determines which operations to perform first, based on a pre-determined precedence. This precedence follows a similar precedence to most programming languages.

Python Programming/Operators

Note that Python adheres to the PEMDAS order of operations.