Allowing to declare postprocessor by python path

harvester/postprocess.py

 from abc import ABC, abstractmethod
 from typing import Dict, Type
 
+from .utils import import_by_path
+
 
 class Postprocessor(ABC):
     def __init__(self, **kwargs):
@@ -17,5 +19,9 @@ POSTPROCESSORS: Dict[str, Type[Postprocessor]] = {
 
 
 def get_postprocessor(config: dict) -> Postprocessor:
-    cls = POSTPROCESSORS[config.pop("type")]
+    type_ = config.pop("type")
+    try:
+        cls = POSTPROCESSORS[type_]
+    except KeyError:
+        cls = import_by_path(type_)
     return cls(**config)

harvester/utils.py

-from typing import Iterator
+import importlib
+from typing import Any, Iterator
 
 from pygeofilter.backends.native.evaluate import NativeEvaluator
 from pygeofilter.parsers.cql_json import parse as json_parse
@@ -13,3 +14,14 @@ def cql_filter(_filter: dict, data: Iterator[dict]) -> Iterator[dict]:
     nat_eval = NativeEvaluator(attribute_map=attr_map, use_getattr=False)
     evaluator = nat_eval.evaluate(_filter)
     yield from filter(evaluator, data)
+
+
+def import_by_path(path: str) -> Any:
+    """Imports the object from the referenced module.
+
+    Args:
+        path (str): the dotted Python path, where the last element is the
+        object in the referenced module.
+    """
+    module_path, _, object_name = path.rpartition(".")
+    return getattr(importlib.import_module(module_path), object_name)