Parent for complex rings

Author: fchapoton

src/sage/rings/complex_double.pyx

@@ -81,10 +81,9 @@ cdef extern from "<complex.h>":
 import sage.rings.abc
 cimport sage.rings.ring
 cimport sage.rings.integer
-from sage.rings.ring import Ring
 
 from sage.structure.element cimport Element, FieldElement
-from sage.structure.parent  cimport Parent
+from sage.structure.parent cimport Parent
 from sage.structure.richcmp cimport rich_to_bool
 from sage.categories.morphism cimport Morphism
 from sage.structure.coerce cimport is_numpy_type
@@ -149,7 +148,8 @@ cdef class ComplexDoubleField_class(sage.rings.abc.ComplexDoubleField):
             (-1.0, -1.0 + 1.2246...e-16*I, False)
         """
         from sage.categories.fields import Fields
-        Ring.__init__(self, self, ('I',), normalize=False, category=Fields().Infinite().Metric().Complete())
+        Parent.__init__(self, self, names=('I',), normalize=False,
+                        category=Fields().Infinite().Metric().Complete())
         self._populate_coercion_lists_()
 
     def __reduce__(self):

src/sage/rings/complex_mpc.pyx

@@ -72,7 +72,6 @@ from sage.structure.element cimport Element
 from sage.structure.richcmp cimport rich_to_bool
 from sage.categories.map cimport Map
 from sage.libs.pari.all import pari
-from sage.rings.ring import Ring
 
 from sage.rings.integer cimport Integer
 from sage.rings.complex_mpfr cimport ComplexNumber
@@ -319,7 +318,8 @@ cdef class MPComplexField_class(sage.rings.ring.Field):
         self.__real_field = real_mpfr.RealField(prec, rnd=_mpfr_rounding_modes[rnd_re(n)])
         self.__imag_field = real_mpfr.RealField(prec, rnd=_mpfr_rounding_modes[rnd_im(n)])
 
-        Ring.__init__(self, self._real_field(), ('I',), False, category=Fields().Infinite())
+        Parent.__init__(self, self._real_field(), names=('I',), normalize=False,
+                        category=Fields().Infinite())
         self._populate_coercion_lists_(coerce_list=[MPFRtoMPC(self._real_field(), self)])
 
     cdef MPComplexNumber _new(self) noexcept: