mol2any: add mol2bool element (#59)

- Add new MolToBool element that converts values to
      a bool array. Can be used for masking.

molpipeline/mol2any/mol2bool.py

@@ -0,0 +1,52 @@
+"""Pipeline elements for converting instances to bool."""
+
+from typing import Any
+
+from molpipeline.abstract_pipeline_elements.core import (
+    MolToAnyPipelineElement,
+    InvalidInstance,
+)
+
+
+class MolToBool(MolToAnyPipelineElement):
+    """Element to generate a bool array from input."""
+
+    def __init__(
+        self,
+        name: str = "Mol2Bool",
+        n_jobs: int = 1,
+        uuid: str | None = None,
+    ) -> None:
+        """Initialize MolToBinaryPipelineElement.
+
+        Parameters
+        ----------
+        name: str, optional (default="Mol2Bool")
+            name of PipelineElement
+        n_jobs: int, optional (default=1)
+            number of jobs to use for parallelization
+        uuid: Optional[str], optional (default=None)
+            uuid of PipelineElement, by default None
+
+        Returns
+        -------
+        None
+        """
+        super().__init__(name=name, n_jobs=n_jobs, uuid=uuid)
+
+    def pretransform_single(self, value: Any) -> bool:
+        """Transform a value to a bool representation.
+
+        Parameters
+        ----------
+        value: Any
+            Value to be transformed to bool representation.
+
+        Returns
+        -------
+        str
+            Binary representation of molecule.
+        """
+        if isinstance(value, InvalidInstance):
+            return False
+        return True

tests/test_elements/test_mol2any/test_mol2bool.py

@@ -0,0 +1,24 @@
+"""Test mol to bool conversion."""
+
+import unittest
+
+from molpipeline.abstract_pipeline_elements.core import InvalidInstance
+from molpipeline.mol2any.mol2bool import MolToBool
+
+
+class TestMolToBool(unittest.TestCase):
+    """Unittest for MolToBool."""
+
+    def test_bool_conversion(self) -> None:
+        """Test if the invalid instances are converted to bool."""
+
+        mol2bool = MolToBool()
+        result = mol2bool.transform(
+            [
+                1,
+                2,
+                InvalidInstance(element_id="test", message="test", element_name="Test"),
+                4,
+            ]
+        )
+        self.assertEqual(result, [True, True, False, True])