rename __relabel -> _relabel

Author: infmagic2047

src/sage/matroids/basis_exchange_matroid.pxd

@@ -15,7 +15,7 @@ cdef class BasisExchangeMatroid(Matroid):
     cdef _weak_invariant_var, _strong_invariant_var, _heuristic_invariant_var
     cdef SetSystem _weak_partition_var, _strong_partition_var, _heuristic_partition_var
 
-    cdef __relabel(self, l)
+    cdef _relabel(self, l)
 
     cdef _pack(self, bitset_t, X)
     cdef __unpack(self, bitset_t)

src/sage/matroids/basis_exchange_matroid.pyx

@@ -191,7 +191,7 @@ cdef class BasisExchangeMatroid(Matroid):
         bitset_free(self._output)
         bitset_free(self._temp)
 
-    cdef __relabel(self, l):
+    cdef _relabel(self, l):
         """
         Relabel each element `e` as `l[e]`, where `l` is a given injective map.
 

src/sage/matroids/basis_matroid.pyx

@@ -557,7 +557,7 @@ cdef class BasisMatroid(BasisExchangeMatroid):
 
         """
         M = BasisMatroid(M=self)
-        M.__relabel(l)
+        M._relabel(l)
         return M
 
     # enumeration