fix new code

Author: fchapoton

src/sage/rings/polynomial/integer_valued_polynomials.py

@@ -1206,11 +1206,12 @@ def variable_shift(self, k=1):
                 A = self.parent()
 
                 def on_basis(n):
-                    return {A._indices(j): binomial(k, n - j) for j in range(n + 1)}
+                    return {A._indices(j): binomial(k, n - j)
+                            for j in range(n + 1)}
 
                 from sage.data_structures.blas_dict import linear_combination
                 mc = self._monomial_coefficients
-                ret = linear_combination((on_basis((index), coeff)
+                ret = linear_combination((on_basis(index), coeff)
                                          for (index, coeff) in mc.items())
                 return A.element_class(A, ret)