feat: add alias for geting and setting model (without s) in StandardS…

…tate

src/autora/state.py

@@ -327,7 +327,12 @@ def _get_value(f, other: Union[Delta, Mapping]):
         >>> from dataclasses import field, dataclass, fields
         >>> @dataclass
         ... class Example:
-        ...     a: int = field()
+        ...     a: int = field()  # base case
+        ...     b: List[int] = field(metadata={"aliases": {"ba": lambda b: [b]}})  # Single alias
+        ...     c: List[int] = field(metadata={"aliases": {
+        ...                                         "ca": lambda x: x,   # pass the value unchanged
+        ...                                         "cb": lambda x: [x]  # wrap the value in a list
+        ...        }})  # Multiple alias
 
         For a field with no aliases, we retrieve values with the base name:
         >>> f_a = fields(Example)[0]
@@ -342,15 +347,104 @@ def _get_value(f, other: Union[Delta, Mapping]):
         >>> _get_value(f_a, Delta(b=2, a=1))
         (1, 'a')
 
+        For fields with an alias, we retrieve values with the base name:
+        >>> f_b = fields(Example)[1]
+        >>> _get_value(f_b, Delta(b=[2]))
+        ([2], 'b')
+
+        ... or for the alias name, transformed by the alias lambda function:
+        >>> _get_value(f_b, Delta(ba=21))
+        ([21], 'ba')
+
+        We preferentially get the base name, and then any aliases:
+        >>> _get_value(f_b, Delta(b=2, ba=21))
+        (2, 'b')
+
+        ... , regardless of their order in the `Delta` object:
+        >>> _get_value(f_b, Delta(ba=21, b=2))
+        (2, 'b')
+
+        Other names are ignored:
+        >>> _get_value(f_b, Delta(a=1))
+        (None, None)
+
+        and the order of other names is unimportant:
+        >>> _get_value(f_b, Delta(a=1, b=2))
+        (2, 'b')
+
+        For fields with multiple aliases, we retrieve values with the base name:
+        >>> f_c = fields(Example)[2]
+        >>> _get_value(f_c, Delta(c=[3]))
+        ([3], 'c')
+
+        ... for any alias:
+        >>> _get_value(f_c, Delta(ca=31))
+        (31, 'ca')
+
+        ... transformed by the alias lambda function :
+        >>> _get_value(f_c, Delta(cb=32))
+        ([32], 'cb')
+
+        ... and ignoring any other names:
+        >>> print(_get_value(f_c, Delta(a=1)))
+        (None, None)
+
+        ... preferentially in the order base name, 1st alias, 2nd alias, ... nth alias:
+        >>> _get_value(f_c, Delta(c=3, ca=31, cb=32))
+        (3, 'c')
+
+        >>> _get_value(f_c, Delta(ca=31, cb=32))
+        (31, 'ca')
+
+        >>> _get_value(f_c, Delta(cb=32))
+        ([32], 'cb')
+
+        >>> print(_get_value(f_c, Delta()))
+        (None, None)
+
+        This works with dict objects:
+        >>> _get_value(f_a, dict(a=13))
+        (13, 'a')
+
+        ... with multiple keys:
+        >>> _get_value(f_b, dict(a=13, b=24, c=35))
+        (24, 'b')
+
+        ... and with aliases:
+        >>> _get_value(f_b, dict(ba=222))
+        ([222], 'ba')
+
+        This works with UserDicts:
+        >>> class MyDelta(UserDict):
+        ...     pass
+
+        >>> _get_value(f_a, MyDelta(a=14))
+        (14, 'a')
+
+        ... with multiple keys:
+        >>> _get_value(f_b, MyDelta(a=1, b=4, c=9))
+        (4, 'b')
+
+        ... and with aliases:
+        >>> _get_value(f_b, MyDelta(ba=234))
+        ([234], 'ba')
+
     """
 
     key = f.name
+    aliases = f.metadata.get("aliases", {})
 
     value, used_key = None, None
 
     if key in other.keys():
         value = other[key]
         used_key = key
+    elif aliases:  # ... is not an empty dict
+        for alias_key, wrapping_function in aliases.items():
+            if alias_key in other:
+                value = wrapping_function(other[alias_key])
+                used_key = alias_key
+                break  # we only evaluate the first match
 
     return value, used_key
 
@@ -405,8 +499,23 @@ def _get_field_names_and_aliases(s: State):
         >>> _get_field_names_and_aliases(SomeState())
         ['l', 'm']
 
+        >>> @dataclass(frozen=True)
+        ... class SomeStateWithAliases(State):
+        ...    l: List = field(default_factory=list, metadata={"aliases": {"l1": None, "l2": None}})
+        ...    m: List = field(default_factory=list, metadata={"aliases": {"m1": None}})
+        >>> _get_field_names_and_aliases(SomeStateWithAliases())
+        ['l', 'l1', 'l2', 'm', 'm1']
+
     """
-    result = [f.name for f in fields(s)]
+    result = []
+
+    for f in fields(s):
+        name = f.name
+        result.append(name)
+
+        aliases = f.metadata.get("aliases", {})
+        result.extend(aliases)
+
     return result
 
 
@@ -1252,6 +1361,20 @@ class StandardState(State):
         >>> (s + dm1 + dm2).models
         [DummyClassifier(constant=1), DummyClassifier(constant=2), DummyClassifier(constant=3)]
 
+        The last model is available under the `model` property:
+        >>> (s + dm1 + dm2).model
+        DummyClassifier(constant=3)
+
+        If there is no model, `None` is returned:
+        >>> print(s.model)
+        None
+
+        `models` can also be updated using a Delta with a single `model`:
+        >>> dm3 = Delta(model=DummyClassifier(constant=4))
+        >>> (s + dm1 + dm3).model
+        DummyClassifier(constant=4)
+
+
         We can use properties X, y, iv_names and dv_names as 'getters' ...
         >>> x_v = Variable('x')
         >>> y_v = Variable('y')
@@ -1280,6 +1403,24 @@ class StandardState(State):
         1  2
         2  3
 
+        However, if the property has a deticated setter, we can still use them as getter:
+        >>> s.model is None
+        True
+
+        >>> from sklearn.linear_model import LinearRegression
+        >>> @on_state
+        ... def add_model(_model):
+        ...     return Delta(model=_model)
+        >>> s = add_model(s, _model=LinearRegression())
+        >>> s.models
+        [LinearRegression()]
+
+        >>> s.model
+        LinearRegression()
+
+
+
+
 
 
     """
@@ -1295,7 +1436,7 @@ class StandardState(State):
     )
     models: List[BaseEstimator] = field(
         default_factory=list,
-        metadata={"delta": "extend"},
+        metadata={"delta": "extend", "aliases": {"model": lambda model: [model]}},
     )
 
     @property
@@ -1392,6 +1533,18 @@ def y(self) -> pd.DataFrame:
             return pd.DataFrame()
         return self.experiment_data[self.dv_names]
 
+    @property
+    def model(self):
+        if len(self.models) == 0:
+            return None
+        # The property to access the backing field
+        return self.models[-1]
+
+    @model.setter
+    def model(self, value):
+        # Control the setting behavior
+        self.models.append(value)
+
 
 X = TypeVar("X")
 Y = TypeVar("Y")