Add __rtruediv__ and __rfloordiv__ to Scalar variables

[Copilot]

Division of a constant by a ScalarVariable (e.g., 1.0 / x or 5.0 // x) was raising TypeError due to missing reverse division operators.

Changes

Scalar variables:

• Added __rtruediv__ method to _scalar_py_operators class, delegating to true_div(other, self)
• Added __rfloordiv__ method to _scalar_py_operators class, delegating to int_div(other, self)
• Added test_rtruediv to verify true division works correctly
• Added test_rfloordiv to verify floor division works correctly

Tensor and XTensor variables:

• Removed legacy Python 2 __div__ and __rdiv__ methods from _tensor_py_operators class in pytensor/tensor/variable.py
• Removed legacy Python 2 __div__ and __rdiv__ methods from XTensorVariable class in pytensor/xtensor/type.py
• Removed unused IntegerDivisionError import

All division operations now use Python 3's modern operators: __truediv__, __floordiv__, __rtruediv__, and __rfloordiv__.

Examples

from pytensor.scalar.basic import ScalarType, TrueDiv, IntDiv

# True division
x = ScalarType(dtype="float64")()
y = 1.0 / x  # Previously raised TypeError, now creates TrueDiv operation
assert isinstance(y.owner.op, TrueDiv)
assert isinstance(y.type, ScalarType)
assert y.eval({x: 2.0}) == 0.5

# Floor division
z = 5.0 // x  # Previously raised TypeError, now creates IntDiv operation
assert isinstance(z.owner.op, IntDiv)
assert isinstance(z.type, ScalarType)
assert z.eval({x: 2.0}) == 2.0

The implementation follows the existing pattern of other reverse arithmetic operators (__radd__, __rsub__, __rmul__, __rpow__).

Original prompt

The user wants to add __rtruediv__ and __rdiv__ to the _scalar_py_operators class in pytensor/scalar/basic.py.

A simple test should also be added to tests/scalar/test_basic.py to cover this new functionality.

This is to fix a bug where division of a constant by a ScalarVariable is unsupported.

The changes to pytensor/scalar/basic.py should be:

    def __rtruediv__(self, other):
        return true_div(other, self)

    def __rdiv__(self, other):
        return true_div(other, self)

These should be added to the _scalar_py_operators class.

And a test case should be added to tests/scalar/test_basic.py like:

def test_rtruediv():
    x = pytensor.scalar.Scalar(dtype="float64")
    y = 1.0 / x
    assert isinstance(y.owner.op, pytensor.scalar.TrueDiv)

This pull request was created as a result of the following prompt from Copilot chat.

The user wants to add __rtruediv__ and __rdiv__ to the _scalar_py_operators class in pytensor/scalar/basic.py.

A simple test should also be added to tests/scalar/test_basic.py to cover this new functionality.

This is to fix a bug where division of a constant by a ScalarVariable is unsupported.

The changes to pytensor/scalar/basic.py should be:

    def __rtruediv__(self, other):
        return true_div(other, self)

    def __rdiv__(self, other):
        return true_div(other, self)

These should be added to the _scalar_py_operators class.

And a test case should be added to tests/scalar/test_basic.py like:

def test_rtruediv():
    x = pytensor.scalar.Scalar(dtype="float64")
    y = 1.0 / x
    assert isinstance(y.owner.op, pytensor.scalar.TrueDiv)

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[ricardoV94]

@copilot changes needed

[ricardoV94]

@copilot remove legacy __div__ and __rdiv__ from tensor (and possibly) sparse variables methods.

[Copilot]

@copilot remove legacy __div__ and __rdiv__ from tensor (and possibly) sparse variables methods.

Fixed in a4881ae. Removed legacy __div__ and __rdiv__ methods from:

• _tensor_py_operators in pytensor/tensor/variable.py
• XTensorVariable in pytensor/xtensor/type.py

Also removed unused IntegerDivisionError import. All division operations now use Python 3 operators (__truediv__, __floordiv__, __rtruediv__, __rfloordiv__).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.68%. Comparing base (60ba7c7) to head (a4881ae).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1701      +/-   ##
==========================================
+ Coverage   81.67%   81.68%   +0.01%     
==========================================
  Files         244      244              
  Lines       53558    53549       -9     
  Branches     9433     9433              
==========================================
  Hits        43741    43741              
+ Misses       7337     7328       -9     
  Partials     2480     2480              

Files with missing lines	Coverage Δ
pytensor/scalar/basic.py	81.05% <100.00%> (+0.03%)	⬆️
pytensor/tensor/variable.py	88.09% <ø> (+1.10%)	⬆️
pytensor/xtensor/type.py	70.19% <ø> (+0.19%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[jessegrabowski]

We don't cast to int here?

[ricardoV94]

This isn't testing the dtype, 2 == 2.0 is true in Python. I trust our old code was doing the correct thing already