polys: drop Poly.slice()

diofant/integrals/risch.py

@@ -743,7 +743,7 @@ def as_poly_1t(p, t, z):
         # a bug.
         raise PolynomialError(f'{p} is not an element of K[{t}, 1/{t}].')
     d = pd.degree(t)
-    one_t_part = pa.slice(0, d + 1)
+    one_t_part = pa % t**(d + 1)
     r = pd.degree() - pa.degree()
     t_part = pa - one_t_part
     t_part = t_part.to_field().exquo(pd)

diofant/polys/polytools.py

@@ -631,18 +631,6 @@ def retract(self, field=None):
                                     extension=not self.domain.is_ExpressionDomain)
         return self.from_dict(rep, *self.gens, domain=dom)
 
-    def slice(self, x, m, n=None):
-        """Take a continuous subsequence of terms of ``self``."""
-        if n is None:
-            j, m, n = 0, x, m
-        else:
-            j = self._gen_to_level(x)
-
-        m, n = int(m), int(n)
-
-        result = self.rep.slice(m, n, j)
-        return self.per(result)
-
     def coeffs(self, order=None):
         """
         Returns all non-zero coefficients from ``self`` in lex order.

diofant/tests/polys/test_polytools.py

@@ -864,22 +864,6 @@ def test_Poly_retract():
     assert Integer(0).as_poly(x, y).retract() == Integer(0).as_poly(x, y)
 
 
-def test_Poly_slice():
-    f = (x**3 + 2*x**2 + 3*x + 4).as_poly()
-
-    assert f.slice(0, 0) == Integer(0).as_poly(x)
-    assert f.slice(0, 1) == Integer(4).as_poly(x)
-    assert f.slice(0, 2) == (3*x + 4).as_poly()
-    assert f.slice(0, 3) == (2*x**2 + 3*x + 4).as_poly()
-    assert f.slice(0, 4) == (x**3 + 2*x**2 + 3*x + 4).as_poly()
-
-    assert f.slice(x, 0, 0) == Integer(0).as_poly(x)
-    assert f.slice(x, 0, 1) == Integer(4).as_poly(x)
-    assert f.slice(x, 0, 2) == (3*x + 4).as_poly()
-    assert f.slice(x, 0, 3) == (2*x**2 + 3*x + 4).as_poly()
-    assert f.slice(x, 0, 4) == (x**3 + 2*x**2 + 3*x + 4).as_poly()
-
-
 def test_Poly_coeffs():
     assert Integer(0).as_poly(x).coeffs() == []
     assert Integer(1).as_poly(x).coeffs() == [1]

docs/release/notes-0.14.rst

@@ -32,6 +32,7 @@ Compatibility breaks
 * Removed unused ``prefixes``, ``postfixes``, ``capture`` and ``variations`` functions, see :pull:`1282` and :pull:`1290`.
 * Drop support for multivariate :class:`~diofant.calculus.order.Order` notion, see :pull:`1296`.
 * Removed ``Add.extract_leading_order`` method, see :pull:`1292`.
+* Removed unused ``slice()`` method of the :class:`~diofant.polys.polytools.Poly`, see :pull:`1318`.
 
 Minor changes
 =============