Merge #32015

Author: Matthias Koeppe

src/sage/interfaces/sympy_wrapper.py

@@ -65,11 +65,11 @@ def _sage_(self):
 
         EXAMPLES::
 
-            sage: F = Set([1, 2])
-            sage: F is Set([1, 2])
+            sage: F = Family([1, 2])
+            sage: F is Family([1, 2])
             False
             sage: sF = F._sympy_(); sF
-            SageSet({1, 2})
+            SageSet(Family (1, 2))
             sage: sF._sage_() is F
             True
         """
@@ -82,7 +82,7 @@ def is_empty(self):
 
         EXAMPLES::
 
-            sage: Empty = Set([])
+            sage: Empty = Family([])
             sage: sEmpty = Empty._sympy_()
             sage: sEmpty.is_empty
             True

src/sage/sets/set.py

@@ -1206,12 +1206,23 @@ def _sympy_(self):
 
             sage: X = Set({1, 2, 3}); X
             {1, 2, 3}
-            sage: X._sympy_()
+            sage: sX = X._sympy_(); sX
             Set(1, 2, 3)
+            sage: sX.is_empty is None
+            True
+
+            sage: Empty = Set([]); Empty
+            {}
+            sage: sEmpty = Empty._sympy_(); sEmpty
+            EmptySet
+            sage: sEmpty.is_empty
+            True
         """
-        from sympy import Set
+        from sympy import Set, EmptySet
         from sage.interfaces.sympy import sympy_init
         sympy_init()
+        if self.is_empty():
+            return EmptySet
         return Set(*[x._sympy_() for x in self])