remove is_isomorphic method

Author: DavidAyotte

src/sage/rings/function_field/drinfeld_modules/drinfeld_module.py

@@ -1267,71 +1267,6 @@ def is_finite(self) -> bool:
         from sage.rings.function_field.drinfeld_modules.finite_drinfeld_module import FiniteDrinfeldModule
         return isinstance(self, FiniteDrinfeldModule)
 
-    def is_isomorphic(self, psi):
-        r"""
-        Return ``True``  whether ``self`` is isomorphic to the other
-        Drinfeld module
-
-        EXAMPLES::
-
-            sage: A = GF(5)['T']
-            sage: K.<T> = Frac(A)
-            sage: c = T^4 + 3*T^2 + T
-            sage: phi = DrinfeldModule(A, [T, T^3, T^9, T])
-            sage: psi = DrinfeldModule(A, [T, c^4*T^3, c^(24)*T^9, c^(124)*T])
-            sage: phi.is_isomorphic(psi)
-            True
-            sage: rho = DrinfeldModule(A, [T, 1, 1, 1])
-            sage: phi.is_isomorphic(rho)
-            False
-
-        ::
-
-            sage: phi = DrinfeldModule(A, [T, 1, 0, 1, 0, 0, 0, T^2, 1, 1])
-            sage: phi.is_isomorphic(phi)
-            True
-            sage: psi = DrinfeldModule(A, [T, 1, 0, 1, 0, T, 0, T^2, 1, 1])
-            sage: phi.is_isomorphic(psi)
-            False
-
-        TESTS::
-
-            sage: F.<a> = GF(5^2)
-            sage: A = F['T']
-            sage: phi = DrinfeldModule(A, [a, 1, 1])
-            sage: psi = DrinfeldModule(A, [Frac(A).gen(), 1, 1])
-            sage: phi.is_isomorphic(psi)
-            Traceback (most recent call last):
-            ...
-            ValueError: categories of the two Drinfeld modules must be the same
-            sage: phi.is_isomorphic(A)
-            Traceback (most recent call last):
-            ...
-            TypeError: input must be a Drinfeld module
-        """
-        if not isinstance(psi, DrinfeldModule):
-            raise TypeError("input must be a Drinfeld module")
-        # Trivial checks:
-        if self.category() != psi.category():
-            raise ValueError("categories of the two Drinfeld modules "
-                             "must be the same")
-        if self._gen == psi._gen:
-            return True
-        if self._gen.degree() != psi._gen.degree():
-            return False
-        if self._gen.degree() == 1:
-            return True
-        # Check if self and psi are patterned alike:
-        if not all(bool(g_self) == bool(g_psi) for g_self, g_psi in\
-            zip(self._gen.coefficients(sparse=False),
-                psi._gen.coefficients(sparse=False))):
-            return False
-        # Check that all the nonzero basic j-invariants agree
-        for p in self.basic_j_invariant_parameters(nonzero=True):
-            if self.j_invariant(p, check=False) != psi.j_invariant(p, check=False):
-                return False
-        return True
-
     def j_invariant(self, parameter=None, check=True):
         r"""
         Return the `j`-invariant of the Drinfeld