Export PartialExtractor

nifty5/__init__.py

@@ -46,7 +46,7 @@ from .operators.outer_product_operator import OuterProduct
 from .operators.simple_linear_operators import (
     VdotOperator, ConjugationOperator, Realizer,
     FieldAdapter, ducktape, GeometryRemover, NullOperator,
-    MatrixProductOperator)
+    MatrixProductOperator, PartialExtractor)
 from .operators.value_inserter import ValueInserter
 from .operators.energy_operators import (
     EnergyOperator, GaussianEnergy, PoissonianEnergy, InverseGammaLikelihood,

nifty5/operators/simple_linear_operators.py

@@ -326,7 +326,7 @@ class NullOperator(LinearOperator):
         return self._nullfield(self._tgt(mode))
 
 
-class _PartialExtractor(LinearOperator):
+class PartialExtractor(LinearOperator):
     def __init__(self, domain, target):
         if not isinstance(domain, MultiDomain):
             raise TypeError("MultiDomain expected")