Improve conditions and refactor dataset classes (#475)

* Reimplement conditions

* Refactor datasets and implement LabelBatch

---------

Co-authored-by: Dario Coscia <dariocos99@gmail.com>

pina/condition/condition.py

@@ -1,10 +1,10 @@
 """Condition module."""
 
-from .domain_equation_condition import DomainEquationCondition
-from .input_equation_condition import InputPointsEquationCondition
-from .input_output_condition import InputOutputPointsCondition
-from .data_condition import DataConditionInterface
 import warnings
+from .data_condition import DataCondition
+from .domain_equation_condition import DomainEquationCondition
+from .input_equation_condition import InputEquationCondition
+from .input_target_condition import InputTargetCondition
 from ..utils import custom_warning_format
 
 # Set the custom format for warnings
@@ -12,6 +12,21 @@ warnings.formatwarning = custom_warning_format
 warnings.filterwarnings("always", category=DeprecationWarning)
 
 
+def warning_function(new, old):
+    """Handle the deprecation warning.
+
+    :param new: Object to use instead of the old one.
+    :type new: str
+    :param old: Object to deprecate.
+    :type old: str
+    """
+    warnings.warn(
+        f"'{old}' is deprecated and will be removed "
+        f"in future versions. Please use '{new}' instead.",
+        DeprecationWarning,
+    )
+
+
 class Condition:
     """
     The class ``Condition`` is used to represent the constraints (physical
@@ -40,16 +55,32 @@ class Condition:
 
     Example::
 
-    >>> TODO
+    >>> from pina import Condition
+    >>> condition = Condition(
+    ...     input=input,
+    ...     target=target
+    ... )
+    >>> condition = Condition(
+    ...     domain=location,
+    ...     equation=equation
+    ... )
+    >>> condition = Condition(
+    ...     input=input,
+    ...     equation=equation
+    ... )
+    >>> condition = Condition(
+    ...     input=data,
+    ...     conditional_variables=conditional_variables
+    ... )
 
     """
 
     __slots__ = list(
         set(
-            InputOutputPointsCondition.__slots__
-            + InputPointsEquationCondition.__slots__
+            InputTargetCondition.__slots__
+            + InputEquationCondition.__slots__
             + DomainEquationCondition.__slots__
-            + DataConditionInterface.__slots__
+            + DataCondition.__slots__
         )
     )
 
@@ -62,25 +93,30 @@ class Condition:
             )
 
         # back-compatibility 0.1
-        if "location" in kwargs.keys():
+        keys = list(kwargs.keys())
+        if "location" in keys:
             kwargs["domain"] = kwargs.pop("location")
-            warnings.warn(
-                f"'location' is deprecated and will be removed "
-                f"in future versions. Please use 'domain' instead.",
-                DeprecationWarning,
-            )
+            warning_function(new="domain", old="location")
+
+        if "input_points" in keys:
+            kwargs["input"] = kwargs.pop("input_points")
+            warning_function(new="input", old="input_points")
+
+        if "output_points" in keys:
+            kwargs["target"] = kwargs.pop("output_points")
+            warning_function(new="target", old="output_points")
 
         sorted_keys = sorted(kwargs.keys())
-
-        if sorted_keys == sorted(InputOutputPointsCondition.__slots__):
-            return InputOutputPointsCondition(**kwargs)
-        elif sorted_keys == sorted(InputPointsEquationCondition.__slots__):
-            return InputPointsEquationCondition(**kwargs)
-        elif sorted_keys == sorted(DomainEquationCondition.__slots__):
+        if sorted_keys == sorted(InputTargetCondition.__slots__):
+            return InputTargetCondition(**kwargs)
+        if sorted_keys == sorted(InputEquationCondition.__slots__):
+            return InputEquationCondition(**kwargs)
+        if sorted_keys == sorted(DomainEquationCondition.__slots__):
             return DomainEquationCondition(**kwargs)
-        elif sorted_keys == sorted(DataConditionInterface.__slots__):
-            return DataConditionInterface(**kwargs)
-        elif sorted_keys == DataConditionInterface.__slots__[0]:
-            return DataConditionInterface(**kwargs)
-        else:
-            raise ValueError(f"Invalid keyword arguments {kwargs.keys()}.")
+        if (
+            sorted_keys == sorted(DataCondition.__slots__)
+            or sorted_keys[0] == DataCondition.__slots__[0]
+        ):
+            return DataCondition(**kwargs)
+
+        raise ValueError(f"Invalid keyword arguments {kwargs.keys()}.")