Where can I find code, that evaluates add and multiplication operations?

[Michał Pawłowski]

Hi.

Where can I find code, that evaluates Add and Mul operations on real numbers? I've found the code in Pow file (sympy/core/power.py). I know that there are move files in that dir:

(sympy/core/add.py)

(sympy/core/mul.py)

But I cannot find the line of evaluation.

I.E. where is code that evaluates expressions such as "2*3"?

Thanks

[Chris Smith]

processing of args, I believe, is handled in Add.flatten and Mul.flatten

/c

[Michał Pawłowski]

Hey, thank you. But flatten is executed only then, when argument is symbol, like 2 * x * x (i.e.). But where is code of numbers eval?

[Chris Smith]

Try follow from `Numbers.__add__`

/c

[David Bailey]

On 05/06/2021 17:09, Chris Smith wrote:
> Try follow from `Numbers.__add__`
>
Since Python can handle arbitrary precision numbers, doesn't the final
evaluation happen in Python? I have always assumed that to be the case. 
E.g. 3*4*x*x is converted into 12*x*x by Python (where x is an instance
of a class) and then SymPy does the rest. Surely that is exactly why
there are problems with expressions such as 2/3x**2 because the
coefficient gets turned into a floating point quantity by Python.

David

[Aaron Meurer]

If you are talking about numerical evaluation, in SymPy, integers wrap
Python integers, so the operations are done in Python itself. Floating
point numbers wrap mpmath, so the code for those will be in the mpmath
library.

Aaron Meurer

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