Fix Attribute error in matrix and polynomial multiplication

[Smit-create]

Fix Attribute error in matrix and polynomial multiplication

References to other Issues or PRs

Fixes #17988

Brief description of what is fixed or changed

Other comments

Release Notes

• polys
  • Changes in Poly.__new__() to make it handle simplified Matrix

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• polys
  • Changes in Poly.__new__() to make it handle simplified Matrix (#18159 by @Smit-create)

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<!-- Your title above should be a short description of what
was changed. Do not include the issue number in the title. -->
Fix Attribute error in matrix and polynomial multiplication
#### References to other Issues or PRs
<!-- If this pull request fixes an issue, write "Fixes #NNNN" in that exact
format, e.g. "Fixes #1234". See
https://github.com/blog/1506-closing-issues-via-pull-requests . Please also
write a comment on that issue linking back to this pull request once it is
open. -->
Fixes #17988

#### Brief description of what is fixed or changed


#### Other comments


#### Release Notes

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<!-- BEGIN RELEASE NOTES -->
* polys
  * Changes in `Poly.__new__()` to make it handle simplified Matrix
<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

[jksuom]

It looks like changing _sympify_it may create errors. Perhaps this would work: No change in decorators but a direct check in Poly.__mul__ as follows

--- a/sympy/polys/polytools.py
+++ b/sympy/polys/polytools.py
@@ -4037,6 +4037,8 @@ def __rsub__(f, g):
 
     @_sympifyit('g', NotImplemented)
     def __mul__(f, g):
+        if not isinstance(g, Expr):
+            return NotImplemented
         if not g.is_Poly:
             try:
                 g = f.__class__(g, *f.gens)
            except PolynomialError:
                return f.as_expr()*g

That should not raise new errors. I think that the changes in Poly.__new__ are good and should be preserved.

[codecov]

Codecov Report

Merging #18159 into master will decrease coverage by 0.029%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##            master    #18159      +/-   ##
============================================
- Coverage   74.953%   74.924%   -0.03%     
============================================
  Files          642       642              
  Lines       166973    166978       +5     
  Branches     39283     39285       +2     
============================================
- Hits        125152    125107      -45     
- Misses       36300     36338      +38     
- Partials      5521      5533      +12

[Smit-create]

It looks like changing _sympify_it may create errors. Perhaps this would work: No change in decorators but a direct check in Poly.__mul__ as follows

--- a/sympy/polys/polytools.py
+++ b/sympy/polys/polytools.py
@@ -4037,6 +4037,8 @@ def __rsub__(f, g):
 
     @_sympifyit('g', NotImplemented)
     def __mul__(f, g):
+        if not isinstance(g, Expr):
+            return NotImplemented
         if not g.is_Poly:
             try:
                 g = f.__class__(g, *f.gens)
            except PolynomialError:
                return f.as_expr()*g

That should not raise new errors. I think that the changes in Poly.__new__ are good and should be preserved.

Yes, It worked. Thanks for your help and reviewing it.

[jksuom]

Thanks for your contribution.