fix private methods used in doctests

Author: infmagic2047

src/sage/libs/lcalc/lcalc_Lfunction.pyx

@@ -251,7 +251,7 @@ cdef class Lfunction:
         """
         return self._compute_rank()
 
-    def __N(self, T):
+    def _N(self, T):
         """
         Compute the number of zeroes upto height `T` using the formula for
         `N(T)` with the error of `S(T)`. Please do not use this. It is only
@@ -262,7 +262,7 @@ cdef class Lfunction:
             sage: from sage.libs.lcalc.lcalc_Lfunction import *
             sage: chi = DirichletGroup(5)[2] #This is a quadratic character
             sage: L=Lfunction_from_character(chi, type="complex")
-            sage: L.__N(10) # abs tol 1e-8
+            sage: L._N(10) # abs tol 1e-8
             4.0
         """
         cdef RealNumber real_T=RRR(T)

src/sage/rings/real_mpfr.pyx

@@ -4300,7 +4300,7 @@ cdef class RealNumber(sage.structure.element.RingElement):
         if (<RealField_class>self._parent)._prec > 10*SIG_PREC_THRESHOLD: sig_off()
         return x
 
-    def __pow(self, RealNumber exponent):
+    def _pow(self, RealNumber exponent):
         """
         Compute ``self`` raised to the power of exponent, rounded in the
         direction specified by the parent of ``self``.
@@ -4309,7 +4309,7 @@ cdef class RealNumber(sage.structure.element.RingElement):
 
             sage: R = RealField(30)
             sage: a = R('1.23456')
-            sage: a.__pow(20.0)
+            sage: a._pow(20.0)
             67.646297
         """
         cdef RealNumber x