Add missing type(...) in _trigsimp_inverse

[adrian-kriegel]

Brief description of what is fixed or changed

Changed isinstance(rv.args[0], g()) to isinstance(rv.args[0], type(g()))
as g() does not return a type and this line would therefore raise a TypeError.

TypeError: isinstance() arg 2 must be a type, a tuple of types, or a union

Release Notes

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#### Brief description of what is fixed or changed
Changed `isinstance(rv.args[0], g())` to `isinstance(rv.args[0], type(g()))` 
as `g()` does not return a type and this line would therefore raise a TypeError.
>> TypeError: isinstance() arg 2 must be a type, a tuple of types, or a union

#### Release Notes
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NO ENTRY
<!-- END RELEASE NOTES -->

[oscarbenjamin]

Do you know of an example that would trigger the error?

[adrian-kriegel]

Do you know of an example that would trigger the error?

cos(x)**2 - haven't looked into why other expressions don't.

from sympy import cos, trigsimp

trigsimp(cos('x')**2, inverse=True)

[oscarbenjamin]

Can you add a test case for the case that fails without this fix?

[adrian-kriegel]

The actual problem is that getattr(rv, 'inverse', None) may sometimes return NoneType (instead of None). This would cause g() to be None.

[oscarbenjamin]

I think the failed job is unrelated (gh-20456) so I restarted the tests.

[github-actions]

Benchmark results from GitHub Actions

Lower numbers are good, higher numbers are bad. A ratio less than 1
means a speed up and greater than 1 means a slowdown. Green lines
beginning with + are slowdowns (the PR is slower then master or
master is slower than the previous release). Red lines beginning
with - are speedups.

Significantly changed benchmark results (PR vs master)

Significantly changed benchmark results (master vs previous release)

| Change   | Before [2487dbb5]    | After [95085aaa]    |   Ratio | Benchmark (Parameter)                                                |
|----------|----------------------|---------------------|---------|----------------------------------------------------------------------|
| -        | 69.9±0.8ms           | 44.0±0.3ms          |    0.63 | integrate.TimeIntegrationRisch02.time_doit(10)                       |
| -        | 68.3±1ms             | 43.3±0.7ms          |    0.63 | integrate.TimeIntegrationRisch02.time_doit_risch(10)                 |
| +        | 18.5±0.2μs           | 29.5±0.2μs          |    1.6  | integrate.TimeIntegrationRisch03.time_doit(1)                        |
| -        | 5.40±0.05ms          | 2.83±0.01ms         |    0.52 | logic.LogicSuite.time_load_file                                      |
| -        | 72.6±0.4ms           | 28.5±0.4ms          |    0.39 | polys.TimeGCD_GaussInt.time_op(1, 'dense')                           |
| -        | 25.8±0.1ms           | 16.9±0.03ms         |    0.65 | polys.TimeGCD_GaussInt.time_op(1, 'expr')                            |
| -        | 73.6±0.5ms           | 29.0±0.2ms          |    0.39 | polys.TimeGCD_GaussInt.time_op(1, 'sparse')                          |
| -        | 256±2ms              | 124±0.7ms           |    0.49 | polys.TimeGCD_GaussInt.time_op(2, 'dense')                           |
| -        | 253±0.9ms            | 126±0.6ms           |    0.5  | polys.TimeGCD_GaussInt.time_op(2, 'sparse')                          |
| -        | 658±5ms              | 371±1ms             |    0.56 | polys.TimeGCD_GaussInt.time_op(3, 'dense')                           |
| -        | 660±2ms              | 374±1ms             |    0.57 | polys.TimeGCD_GaussInt.time_op(3, 'sparse')                          |
| -        | 503±2μs              | 289±0.7μs           |    0.58 | polys.TimeGCD_LinearDenseQuadraticGCD.time_op(1, 'dense')            |
| -        | 1.79±0.01ms          | 1.03±0.01ms         |    0.58 | polys.TimeGCD_LinearDenseQuadraticGCD.time_op(2, 'dense')            |
| -        | 5.79±0.02ms          | 3.10±0.01ms         |    0.54 | polys.TimeGCD_LinearDenseQuadraticGCD.time_op(3, 'dense')            |
| -        | 453±0.5μs            | 229±0.7μs           |    0.51 | polys.TimeGCD_QuadraticNonMonicGCD.time_op(1, 'dense')               |
| -        | 1.50±0.01ms          | 693±5μs             |    0.46 | polys.TimeGCD_QuadraticNonMonicGCD.time_op(2, 'dense')               |
| -        | 4.90±0.05ms          | 1.64±0.01ms         |    0.33 | polys.TimeGCD_QuadraticNonMonicGCD.time_op(3, 'dense')               |
| -        | 374±2μs              | 204±1μs             |    0.55 | polys.TimeGCD_SparseGCDHighDegree.time_op(1, 'dense')                |
| -        | 2.46±0.01ms          | 1.21±0ms            |    0.49 | polys.TimeGCD_SparseGCDHighDegree.time_op(3, 'dense')                |
| -        | 9.95±0.04ms          | 4.33±0.03ms         |    0.44 | polys.TimeGCD_SparseGCDHighDegree.time_op(5, 'dense')                |
| -        | 364±3μs              | 169±1μs             |    0.46 | polys.TimeGCD_SparseNonMonicQuadratic.time_op(1, 'dense')            |
| -        | 2.53±0.01ms          | 894±5μs             |    0.35 | polys.TimeGCD_SparseNonMonicQuadratic.time_op(3, 'dense')            |
| -        | 9.61±0.07ms          | 2.66±0.03ms         |    0.28 | polys.TimeGCD_SparseNonMonicQuadratic.time_op(5, 'dense')            |
| -        | 1.06±0.01ms          | 429±2μs             |    0.4  | polys.TimePREM_LinearDenseQuadraticGCD.time_op(3, 'dense')           |
| -        | 1.72±0.01ms          | 507±2μs             |    0.29 | polys.TimePREM_LinearDenseQuadraticGCD.time_op(3, 'sparse')          |
| -        | 5.94±0.04ms          | 1.79±0.02ms         |    0.3  | polys.TimePREM_LinearDenseQuadraticGCD.time_op(5, 'dense')           |
| -        | 8.42±0.1ms           | 1.53±0ms            |    0.18 | polys.TimePREM_LinearDenseQuadraticGCD.time_op(5, 'sparse')          |
| -        | 284±2μs              | 65.4±0.5μs          |    0.23 | polys.TimePREM_QuadraticNonMonicGCD.time_op(1, 'sparse')             |
| -        | 3.48±0.03ms          | 399±3μs             |    0.11 | polys.TimePREM_QuadraticNonMonicGCD.time_op(3, 'dense')              |
| -        | 3.99±0.07ms          | 283±2μs             |    0.07 | polys.TimePREM_QuadraticNonMonicGCD.time_op(3, 'sparse')             |
| -        | 6.95±0.1ms           | 1.26±0.01ms         |    0.18 | polys.TimePREM_QuadraticNonMonicGCD.time_op(5, 'dense')              |
| -        | 8.72±0.03ms          | 844±3μs             |    0.1  | polys.TimePREM_QuadraticNonMonicGCD.time_op(5, 'sparse')             |
| -        | 5.32±0.1ms           | 2.98±0.01ms         |    0.56 | polys.TimeSUBRESULTANTS_LinearDenseQuadraticGCD.time_op(2, 'sparse') |
| -        | 12.1±0.04ms          | 6.57±0.06ms         |    0.54 | polys.TimeSUBRESULTANTS_LinearDenseQuadraticGCD.time_op(3, 'dense')  |
| -        | 22.3±0.04ms          | 9.09±0.02ms         |    0.41 | polys.TimeSUBRESULTANTS_LinearDenseQuadraticGCD.time_op(3, 'sparse') |
| -        | 5.18±0.02ms          | 868±2μs             |    0.17 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(1, 'sparse')    |
| -        | 12.5±0.06ms          | 7.10±0.02ms         |    0.57 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(2, 'sparse')    |
| -        | 102±0.4ms            | 25.9±0.1ms          |    0.25 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(3, 'dense')     |
| -        | 166±1ms              | 53.7±0.2ms          |    0.32 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(3, 'sparse')    |
| -        | 176±3μs              | 113±0.6μs           |    0.64 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(1, 'dense')      |
| -        | 356±3μs              | 216±1μs             |    0.61 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(1, 'sparse')     |
| -        | 4.33±0.06ms          | 843±4μs             |    0.19 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(3, 'dense')      |
| -        | 5.27±0.02ms          | 388±2μs             |    0.07 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(3, 'sparse')     |
| -        | 20.1±0.3ms           | 2.81±0.01ms         |    0.14 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(5, 'dense')      |
| -        | 23.0±0.2ms           | 630±2μs             |    0.03 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(5, 'sparse')     |
| -        | 482±2μs              | 136±1μs             |    0.28 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(1, 'sparse') |
| -        | 4.72±0.06ms          | 611±2μs             |    0.13 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(3, 'dense')  |
| -        | 5.30±0.03ms          | 141±3μs             |    0.03 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(3, 'sparse') |
| -        | 13.3±0.3ms           | 1.30±0.02ms         |    0.1  | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(5, 'dense')  |
| -        | 14.1±0.2ms           | 145±2μs             |    0.01 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(5, 'sparse') |
| -        | 136±0.6μs            | 74.5±0.8μs          |    0.55 | solve.TimeMatrixOperations.time_rref(3, 0)                           |
| -        | 256±0.9μs            | 89.2±1μs            |    0.35 | solve.TimeMatrixOperations.time_rref(4, 0)                           |
| -        | 24.0±0.09ms          | 9.98±0.2ms          |    0.42 | solve.TimeSolveLinSys189x49.time_solve_lin_sys                       |
| -        | 28.3±0.1ms           | 15.4±0.08ms         |    0.54 | solve.TimeSparseSystem.time_linsolve_Aaug(20)                        |
| -        | 55.3±0.4ms           | 24.8±0.1ms          |    0.45 | solve.TimeSparseSystem.time_linsolve_Aaug(30)                        |
| -        | 28.3±0.1ms           | 15.0±0.2ms          |    0.53 | solve.TimeSparseSystem.time_linsolve_Ab(20)                          |
| -        | 55.1±0.4ms           | 24.5±0.1ms          |    0.44 | solve.TimeSparseSystem.time_linsolve_Ab(30)                          |

Full benchmark results can be found as artifacts in GitHub Actions
(click on checks at the top of the PR).

[oscarbenjamin]

The actual problem is that getattr(rv, 'inverse', None) may sometimes return NoneType (instead of None)

When does that happen? Maybe that should be fixed rather than trying to handle it here.