add ReadData

ipsuite/data_loading/__init__.py

@@ -1,6 +1,6 @@
 """ipsuite data loading module."""
 
-from ipsuite.data_loading.add_data_ase import AddData
+from ipsuite.data_loading.add_data_ase import AddData, ReadData
 from ipsuite.data_loading.add_data_h5md import AddDataH5MD
 
-__all__ = ["AddData", "AddDataH5MD"]
+__all__ = ["AddData", "AddDataH5MD", "ReadData"]

ipsuite/data_loading/add_data_ase.py

@@ -1,5 +1,6 @@
 """ipsuite data loading with ASE."""
 
+import functools
 import logging
 import pathlib
 import typing
@@ -41,6 +42,32 @@ def load_data(
     return atoms
 
 
+class ReadData(base.IPSNode):
+    """Read data without converting it to H5MD.
+
+    This Node can be used instead of `AddData` to avoid
+    initial conversion to H5MD. Later Nodes might still
+    convert the data to H5MD.
+
+    Attributes
+    ----------
+    file: str|Path
+        path to the file that should be read.
+    lines_to_read: int, optional
+        maximal number of lines/configurations to read, None for read all
+    """
+
+    file: typing.Union[str, pathlib.Path] = zntrack.deps_path()
+    lines_to_read: int = zntrack.params(None)
+
+    def run(self):
+        pass
+
+    @functools.cached_property
+    def atoms(self) -> typing.List[ase.Atoms]:
+        return load_data(self.file, self.lines_to_read)
+
+
 class AddData(base.IPSNode):
     """Add data using ASE.
 

ipsuite/nodes.py

@@ -42,6 +42,7 @@ class _Nodes:
     # Data
     AddData = "ipsuite.data_loading.AddData"
     AddDataH5MD = "ipsuite.data_loading.AddDataH5MD"
+    ReadData = "ipsuite.data_loading.ReadData"
 
     # Bootstrap
     RattleAtoms = "ipsuite.bootstrap.RattleAtoms"

tests/integration/test_AddData.py

@@ -19,14 +19,21 @@ def test_AddData(proj_path, traj_file, atoms_list, eager):
     subprocess.check_call(["dvc", "add", traj_file.name])
     with ipsuite.Project() as project:
         data = ipsuite.AddData(file=traj_file.name)
+        data2 = ipsuite.data_loading.ReadData(file=traj_file.name)
 
     project.run(eager=eager)
     if not eager:
         data.load()
+        data2.load()
 
     assert isinstance(data.atoms, list)
     assert isinstance(data.atoms[0], ase.Atoms)
 
+    assert isinstance(data2.atoms, list)
+    assert isinstance(data2.atoms[0], ase.Atoms)
+
+    assert data.atoms == data2.atoms
+
     for loaded, given in zip(data.atoms[:], atoms_list):
         # Check that the atoms match
         assert loaded.get_potential_energy() == given.get_potential_energy()