fix data module + add tests

Author: GiovanniCanali

docs/source/_rst/data/data_module.rst

@@ -2,6 +2,6 @@ DataModule
 ======================
 .. currentmodule:: pina.data.data_module
 
-.. autoclass:: pina._src.data.data_module.PinaDataModule
+.. autoclass:: pina._src.data.data_module.DataModule
     :members:
     :show-inheritance:

pina/__init__.py

@@ -1,6 +1,4 @@
 """
-PINA: Physics-Informed Neural Analysis.
-
 A specialized framework for Scientific Machine Learning (SciML), providing
 tools for Physics-Informed Neural Networks (PINNs), Neural Operators,
 and data-driven physical modeling.
@@ -10,12 +8,31 @@
     "LabelTensor",
     "Trainer",
     "Condition",
-    "PinaDataModule",
+    "DataModule",
     "Graph",
 ]
 
 from pina._src.core.label_tensor import LabelTensor
 from pina._src.core.graph import Graph
 from pina._src.core.trainer import Trainer
 from pina._src.condition.condition import Condition
-from pina._src.data.data_module import PinaDataModule
+from pina._src.data.data_module import DataModule
+
+
+# Back-compatibility with version 0.2, to be removed soon
+import warnings
+
+_DEPRECATED_IMPORTS = {"PinaDataModule": "DataModule"}
+
+
+def __getattr__(name):
+    if name in _DEPRECATED_IMPORTS:
+
+        warnings.warn(
+            f"Importing '{name}' from 'pina' is deprecated; use "
+            f"pina.{_DEPRECATED_IMPORTS[name]} instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+
+        return globals()[_DEPRECATED_IMPORTS[name]]

pina/_src/core/trainer.py

@@ -18,6 +18,9 @@
 warnings.formatwarning = custom_warning_format
 warnings.filterwarnings("always", category=UserWarning)
 
+# TODO: add checks on training, val and test sizes
+# TODO: rimuovi tutti i check inutili a cascata in tutto il data module
+
 
 class Trainer(lightning.pytorch.Trainer):
     """
@@ -69,7 +72,7 @@ def __init__(
         :param bool automatic_batching: If ``True``, automatic PyTorch batching
             is performed, otherwise the items are retrieved from the dataset
             all at once. For further details, see the
-            :class:`~pina.data.data_module.PinaDataModule` class. Default is
+            :class:`~pina.data.data_module.DataModule` class. Default is
             ``False``.
         :param int num_workers: The number of worker threads for data loading.
             Default is ``0`` (serial loading).
@@ -248,7 +251,7 @@ def _create_datamodule(
                 "are sampled. The Trainer got the following:\n"
                 f"{error_message}"
             )
-        self.data_module = PinaDataModule(
+        self.data_module = DataModule(
             self.solver.problem,
             train_size=train_size,
             test_size=test_size,