Adapt Mathics interface to SymPy upgrade from 1.8 to 1.10 (resp.1.9)

[soehms]

Since this upgrade of SymPy (especially by this commit) the Mathics interface is broken:

sage: slist = [[1, 2], 3., 4 + I]
sage: mlist = mathics(slist)
sage: mlist.sage()
Traceback (most recent call last):
...
NotImplementedError: conversion to SageMath is not implemented

Here we implement a fix of that.

Component: interfaces

Keywords: Mathics inteface SymPy

Author: Sebastian Oehms

Branch/Commit: 4302109

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/33584

[soehms]

Branch: u/soehms/mathics_sympy_upgr_33584

[soehms]

comment:2

No additional tests needed, since they are already there!

[soehms]

Commit: 4302109

[soehms]

Author: Sebastian Oehms

[mkoeppe]

Reviewer: Matthias Koeppe

[mkoeppe]

comment:3

LGTM

[soehms]

comment:4

Thanks!

[sheerluck]

comment:5

I use this patch

--- a/sage/interfaces/sympy.py
+++ b/sage/interfaces/sympy.py
@@ -259,6 +259,12 @@
         return SR.var(str(self))
 
 
+def _sympysage_mathics_expression(self):
+    from sage.interfaces.mathics import reduce_load
+    return [reduce_load(x)._sage_()
+            for x in self.expr.to_python()]
+
+
 def _sympysage_Subs(self):
     """
     EXAMPLES::
@@ -302,7 +308,7 @@
 
         else:
             # the function defined in sympy is not known in sage
-            raise AttributeError
+            raise AttributeError(fname)
     return func
 
 # the convoluted class structure with metaclasses and stuff sympy uses
@@ -941,6 +947,8 @@
     from sympy.polys.rootoftools import CRootOf
     from sympy.series.order import Order
     from sympy.matrices import ImmutableMatrix, ImmutableSparseMatrix, Matrix, SparseMatrix
+    from mathics.core.convert import SympyExpression
+    SympyExpression._sage_ = _sympysage_mathics_expression
 
     Float._sage_ = _sympysage_float
     Integer._sage_ = _sympysage_integer

but I am not saying that it's correct so I couldn't show it to anybody

[soehms]

comment:6

Replying to @sheerluck:

I use this patch

--- a/sage/interfaces/sympy.py
+++ b/sage/interfaces/sympy.py
@@ -259,6 +259,12 @@
         return SR.var(str(self))
 
 
+def _sympysage_mathics_expression(self):
+    from sage.interfaces.mathics import reduce_load
+    return [reduce_load(x)._sage_()
+            for x in self.expr.to_python()]
+
+
 def _sympysage_Subs(self):
     """
     EXAMPLES::
@@ -302,7 +308,7 @@
 
         else:
             # the function defined in sympy is not known in sage
-            raise AttributeError
+            raise AttributeError(fname)
     return func
 
 # the convoluted class structure with metaclasses and stuff sympy uses
@@ -941,6 +947,8 @@
     from sympy.polys.rootoftools import CRootOf
     from sympy.series.order import Order
     from sympy.matrices import ImmutableMatrix, ImmutableSparseMatrix, Matrix, SparseMatrix
+    from mathics.core.convert import SympyExpression
+    SympyExpression._sage_ = _sympysage_mathics_expression
 
     Float._sage_ = _sympysage_float
     Integer._sage_ = _sympysage_integer

but I am not saying that it's correct so I couldn't show it to anybody

I agree that this fixes the issue, as well. Probably you know better about Mathics than I do, but it seems to be more restrictive, since it converts each instance of SympyExpression to a list. Furthermore, the import statement may fail, since Mathics is an optional package. Thus, it has to be checked that the feature is present.

Anyway, you are welcome to contribute to the code. But I would prefer to do that on a separate ticket, to have the issue fixed, as soon as possible.

[sheerluck]

comment:7

I agree that my patch is a dirty hack :)

I agree that proper work with SympyExpression should be on on a separate ticket.

I agree that this ticket should be merged ASAP.

[vbraun]

Changed branch from u/soehms/mathics_sympy_upgr_33584 to 4302109