sage.{modular,quadratic_forms}: Fix up replacement of is_{Real,Comple…

…x}[Double]Field

src/sage/modular/dirichlet.py

@@ -1153,7 +1153,7 @@ def _pari_init_(self):
 
         # now compute the input for pari (list of exponents)
         P = self.parent()
-        if isinstance(P.base_ring(, sage.rings.abc.ComplexField)):
+        if isinstance(P.base_ring(), sage.rings.abc.ComplexField):
             zeta = P.zeta()
             zeta_argument = zeta.argument()
             v = [int(x.argument() / zeta_argument) for x in values_on_gens]
@@ -2138,7 +2138,7 @@ def element(self):
         """
         P = self.parent()
         M = P._module
-        if isinstance(P.base_ring(, sage.rings.abc.ComplexField)):
+        if isinstance(P.base_ring(), sage.rings.abc.ComplexField):
             zeta = P.zeta()
             zeta_argument = zeta.argument()
             v = M([int(round(x.argument() / zeta_argument))

src/sage/quadratic_forms/special_values.py

@@ -9,7 +9,6 @@
 
 from sage.combinat.combinat import bernoulli_polynomial
 from sage.misc.functional import denominator
-from sage.rings.all import RealField
 from sage.arith.all import kronecker_symbol, bernoulli, factorial, fundamental_discriminant
 from sage.rings.infinity import infinity
 from sage.rings.integer_ring import ZZ
@@ -278,9 +277,10 @@ def quadratic_L_function__numerical(n, d, num_terms=1000):
         ....:         print("Oops! We have a problem at d = {}: exact = {}, numerical = {}".format(d, RR(quadratic_L_function__exact(1, d)), RR(quadratic_L_function__numerical(1, d))))
     """
     # Set the correct precision if it is given (for n).
-    if isinstance(n.parent(, sage.rings.abc.RealField)):
+    if isinstance(n.parent(), sage.rings.abc.RealField):
         R = n.parent()
     else:
+        from sage.rings.real_mpfr import RealField
         R = RealField()
 
     if n < 0: