Basic.as_poly method moved to Expr.as_poly

diofant/core/basic.py

@@ -479,31 +479,6 @@ def _sorted_args(self):
         """
         return self.args
 
-    def as_poly(self, *gens, **args):
-        """Converts ``self`` to a polynomial or returns ``None``.
-
-        Examples
-        ========
-
-        >>> from diofant import sin
-        >>> from diofant.abc import x, y
-
-        >>> (x**2 + x*y).as_poly()
-        Poly(x**2 + x*y, x, y, domain='ZZ')
-
-        >>> (x**2 + x*y).as_poly(x, y)
-        Poly(x**2 + x*y, x, y, domain='ZZ')
-
-        >>> (x**2 + sin(y)).as_poly(x, y) is None
-        True
-        """
-        from ..polys import Poly, PolynomialError
-
-        try:
-            return Poly(self, *gens, **args)
-        except PolynomialError:
-            pass
-
     def subs(self, *args, **kwargs):
         """
         Substitutes old for new in an expression after sympifying args.

diofant/core/expr.py

@@ -1362,6 +1362,31 @@ def as_expr(self, *gens):
         """
         return self
 
+    def as_poly(self, *gens, **args):
+        """Converts ``self`` to a polynomial or returns ``None``.
+
+        Examples
+        ========
+
+        >>> from diofant import sin
+        >>> from diofant.abc import x, y
+
+        >>> (x**2 + x*y).as_poly()
+        Poly(x**2 + x*y, x, y, domain='ZZ')
+
+        >>> (x**2 + x*y).as_poly(x, y)
+        Poly(x**2 + x*y, x, y, domain='ZZ')
+
+        >>> (x**2 + sin(y)).as_poly(x, y) is None
+        True
+        """
+        from ..polys import Poly, PolynomialError
+
+        try:
+            return Poly(self, *gens, **args)
+        except PolynomialError:
+            pass
+
     def as_coefficient(self, expr):
         """Extracts symbolic coefficient at the given expression.