DEP: remove _is_number(Expr) from expr.pyi file

[Zeroto521]

_is_number(Expr) always return False. Because Expr doesn't have __float__ method and it isn't a number type.

In [1]: from pyscipopt import Model, Expr

In [2]: from pyscipopt.scip import CONST

In [3]: e = Expr({CONST: -1.0})

In [4]: float(e)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[4], line 1
----> 1 float(e)

TypeError: float() argument must be a string or a real number, not 'pyscipopt.scip.Expr'

In [5]: float(e+1)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[5], line 1
----> 1 float(e+1)

TypeError: float() argument must be a string or a real number, not 'pyscipopt.scip.Expr'

[Copilot]

Pull request overview

This PR removes dead code from the Expr class by eliminating checks for _is_number(self) which always return False since Expr instances cannot be converted to float.

Changes:

• Removed unreachable code branches in __add__, __mul__, and __rtruediv__ methods that checked if self is a number
• Simplified __rtruediv__ implementation by removing the always-false conditional check

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Zeroto521]

This pr is ready.
CI fails due to performance jitter. Especially, the traceline mark is set to True.

=========================== short test summary info ============================
FAILED tests/test_matrix_variable.py::test_matrix_dot_performance[50] - assert False
 +  where False = isGT(2.9845094680786133, 3.222688674926758)
 +    where isGT = <pyscipopt.scip.Model object at 0x7f039845b440>.isGT
FAILED tests/test_matrix_variable.py::test_matrix_dot_performance[100] - assert False
 +  where False = isGT(25.479017972946167, 25.84245491027832)
 +    where isGT = <pyscipopt.scip.Model object at 0x7f0364f4b5c0>.isGT
= 2 failed, 408 passed, 104 skipped, 11 xfailed, 4 warnings in 157.89s (0:02:37) =
/opt/hostedtoolcache/Python/3.11.14/x64/lib/python3.11/site-packages/coverage/control.py:958: CoverageWarning: No data was collected. (no-data-collected); see https://coverage.readthedocs.io/en/7.13.1/messages.html#warning-no-data-collected
  self._warn("No data was collected.", slug="no-data-collected")

[Joao-Dionisio]

isGT(2.9845094680786133, 3.222688674926758) the difference here seems quite significant, no?

[Joao-Dionisio]

Same failures. Can you please try with and without your changes locally and report back, please?

[Zeroto521]

GitHub and local test as below for 532dee4
pytest is the core problem that causes CI to fail. And trace and pytest-xdist also slow it down.

from time import time

import numpy as np

from pyscipopt import Model

n = 50

model = Model()
x = model.addMatrixVar((n, n))
a = np.random.rand(n, n)

env	TRACE	test method	n	a @ x.view(np.ndarray)	a @ x
github	1	pytest -n auto tests/test_matrix_variable.py::test_matrix_dot_performance	50	2.9845s	3.2226s
github	1	pytest -n auto tests/test_matrix_variable.py::test_matrix_dot_performance	100	25.4790s	25.8424s
local	0	python test.py	50	0.0898s	0.0752s
local	0	python test.py	100	1.3043s	0.9023s
local	0	pytest tests/test_matrix_variable.py::test_matrix_dot_performance -s	50	0.0936s	0.0984s
local	0	pytest tests/test_matrix_variable.py::test_matrix_dot_performance -s	100	0.9914s	0.7366s
local	1	python test.py	50	0.0957s	0.0762s
local	1	python test.py	100	1.5692s	1.0288s
local	1	pytest tests/test_matrix_variable.py::test_matrix_dot_performance -s	50	0.0911s	0.0837s
local	1	pytest tests/test_matrix_variable.py::test_matrix_dot_performance -s	100	1.0898s	0.9659s

conda env

# packages in environment at D:\Users\Zero\AppData\Local\miniforge3\envs\cy310:
#
# Name                            Version             Build                  Channel
bzip2                             1.0.8               h0ad9c76_8             conda-forge
ca-certificates                   2025.11.12          h4c7d964_0             conda-forge
certifi                           2025.11.12          pypi_0                 pypi
charset-normalizer                3.4.4               pypi_0                 pypi
colorama                          0.4.6               pyhd8ed1ab_1           conda-forge
cython                            3.2.3               py310h23e71ea_0        conda-forge
exceptiongroup                    1.3.1               pyhd8ed1ab_0           conda-forge
execnet                           2.1.2               pyhd8ed1ab_0           conda-forge
idna                              3.11                pypi_0                 pypi
iniconfig                         2.3.0               pyhd8ed1ab_0           conda-forge
libblas                           3.9.0               35_h5709861_mkl        conda-forge
libcblas                          3.9.0               35_h2a3cdd5_mkl        conda-forge
libexpat                          2.7.3               hac47afa_0             conda-forge
libffi                            3.5.2               h52bdfb6_0             conda-forge
libhwloc                          2.11.2              default_hc8275d1_1000  conda-forge
libiconv                          1.18                hc1393d2_2             conda-forge
liblapack                         3.9.0               35_hf9ab0e9_mkl        conda-forge
liblzma                           5.8.1               h2466b09_2             conda-forge
libpython                         0.2                 pypi_0                 pypi
libpython-static                  3.10.19             hac47afa_2_cpython     conda-forge
libsqlite                         3.51.1              hf5d6505_1             conda-forge
libxml2                           2.13.9              h741aa76_0             conda-forge
libzlib                           1.3.1               h2466b09_2             conda-forge
llvm-openmp                       21.1.8              h4fa8253_0             conda-forge
m2w64-binutils                    2.25.1              5                      conda-forge
m2w64-bzip2                       1.0.6               6                      conda-forge
m2w64-crt-git                     5.0.0.4636.2595836  2                      conda-forge
m2w64-gcc                         5.3.0               6                      conda-forge
m2w64-gcc-ada                     5.3.0               6                      conda-forge
m2w64-gcc-fortran                 5.3.0               6                      conda-forge
m2w64-gcc-libgfortran             5.3.0               6                      conda-forge
m2w64-gcc-libs                    5.3.0               7                      conda-forge
m2w64-gcc-libs-core               5.3.0               7                      conda-forge
m2w64-gcc-objc                    5.3.0               6                      conda-forge
m2w64-gmp                         6.1.0               2                      conda-forge
m2w64-headers-git                 5.0.0.4636.c0ad18a  2                      conda-forge
m2w64-isl                         0.16.1              2                      conda-forge
m2w64-libiconv                    1.14                6                      conda-forge
m2w64-libmangle-git               5.0.0.4509.2e5a9a2  2                      conda-forge
m2w64-libwinpthread-git           5.0.0.4634.697f757  2                      conda-forge
m2w64-make                        4.1.2351.a80a8b8    2                      conda-forge
m2w64-mpc                         1.0.3               3                      conda-forge
m2w64-mpfr                        3.1.4               4                      conda-forge
m2w64-pkg-config                  0.29.1              2                      conda-forge
m2w64-toolchain                   5.3.0               7                      conda-forge
m2w64-tools-git                   5.0.0.4592.90b8472  2                      conda-forge
m2w64-windows-default-manifest    6.4                 3                      conda-forge
m2w64-winpthreads-git             5.0.0.4634.697f757  2                      conda-forge
m2w64-zlib                        1.2.8               10                     conda-forge
mkl                               2024.2.2            h57928b3_16            conda-forge
msys2-conda-epoch                 20160418            1                      conda-forge
numpy                             2.2.6               py310h4987827_0        conda-forge
openssl                           3.6.0               h725018a_0             conda-forge
packaging                         25.0                pyh29332c3_1           conda-forge
pip                               25.3                pyh8b19718_0           conda-forge
pluggy                            1.6.0               pyhf9edf01_1           conda-forge
pthreads-win32                    2.9.1               h2466b09_4             conda-forge
pygments                          2.19.2              pyhd8ed1ab_0           conda-forge
pytest                            9.0.2               pyhcf101f3_0           conda-forge
pytest-xdist                      3.8.0               pyhd8ed1ab_0           conda-forge
python                            3.10.19             hc20f281_2_cpython     conda-forge
python_abi                        3.10                8_cp310                conda-forge
requests                          2.32.5              pypi_0                 pypi
setuptools                        80.9.0              pyhff2d567_0           conda-forge
tbb                               2021.13.0           h62715c5_1             conda-forge
tk                                8.6.13              h2c6b04d_3             conda-forge
tomli                             2.3.0               pyhcf101f3_0           conda-forge
typing_extensions                 4.15.0              pyhcf101f3_0           conda-forge
tzdata                            2025c               h8577fbf_0             conda-forge
ucrt                              10.0.26100.0        h57928b3_0             conda-forge
urllib3                           2.6.2               pypi_0                 pypi
vc                                14.3                h2b53caa_33            conda-forge
vc14_runtime                      14.44.35208         h818238b_33            conda-forge
vcomp14                           14.44.35208         h818238b_33            conda-forge
wheel                             0.45.1              pyhd8ed1ab_1           conda-forge

[Joao-Dionisio]

This is once again failing: https://github.com/scipopt/PySCIPOpt/actions/runs/21707369612/job/62601818671

@Zeroto521 , the test needs to be changed so that it passes consistently. Either that, or we revert this change. The gain, if it exists, seems very minimal.

[Zeroto521]

This is once again failing: https://github.com/scipopt/PySCIPOpt/actions/runs/21707369612/job/62601818671

@Zeroto521 , the test needs to be changed so that it passes consistently. Either that, or we revert this change. The gain, if it exists, seems very minimal.

@Joao-Dionisio I perfer to drop all performance test cases in CI. These test cases can't show the performance gain in CI environment, but they will cause CI failing.