I use the new matmul @ operator to implement units, for example 1@u_s for 1 second ( see alpha state implementation at https://github.com/FabriceSalvaire/PySpice/tree/master/PySpice/Unit ).

It looks cool, but unfortunately 10@u_s / 2@u_s is actually interpreted as (10@u_s / 2)@u_s instead of (10@u_s) / (2@u_s) due to operator precedence + <<< - <<< * <<< @ <<< / <<< // <<< % https://docs.python.org/3/reference/expressions.html#operator-precedence

Since Python is widely used for scientific applications, would it be possible to investigate this topic ?

Operator precedence cannot change without breaking existing code.

Precedence issues when dealing with units is unavoidable, I think. The units program on Linux/Unix has similar issues, and they write their own parser and choose their own precedence.

https://www.gnu.org/software/units/manual/html_node/Operators.html

As Eric says, we can't change the precedence of the @ operator easily, if at all. It would likely require at least one full release (3.8) with a warning, or a future import, and frankly if the numpy community is against it you'll have zero chance of it happening. (On the other hand, if they're in favour of it, you'll have a good chance.)

If you still want to pursue this idea further, please take the idea to the numpy and/or Python-Ideas mailing lists for further discussion:

https://www.scipy.org/scipylib/mailing-lists.html

https://mail.python.org/mailman/listinfo/python-ideas

but for now I'm going to set the issue to pending.

[Steven]
> please take the idea to the numpy and/or Python-Ideas mailing lists for further discussion:

But please do read through the previous discussions before starting a new one! See the links in PEP 465, and particularly https://mail.scipy.org/pipermail/numpy-discussion/2014-March/069444.html

Gah! Forgot that my post would reset this issue to open. I'm going to close here, since this would be a sufficiently big and unlikely change that it's not going to happen without a python-ideas/python-dev discussion.

stage: resolved

nosy: + steven.daprano
messages: + msg315923

resolution: postponed

messages: + msg315922

type: behavior -> enhancement