Deprecate initialize_data_collector

docs/migration_guide.md

@@ -295,3 +295,19 @@ def show_steps(model):
 
 SolaraViz(model, components=[show_steps])
 ```
+
+### Other changes
+#### Removal of Model.initialize_data_collector
+The `initialize_data_collector` in the Model class is removed. In the Model class, replace:
+
+Replace:
+```python
+self.initialize_data_collector(...)
+```
+
+With:
+```python
+self.datacollector = DataCollector(...)
+```
+
+- Ref: [PR #2327](https://github.com/projectmesa/mesa/pull/2327), Mesa-examples [PR #208](https://github.com/projectmesa/mesa-examples/pull/208))

mesa/batchrunner.py

@@ -38,6 +38,9 @@
     Returns:
         List[Dict[str, Any]]
 
+    Notes:
+        batch_run assumes the model has a `datacollector` attribute that has a DataCollector object initialized.
+
     """
     runs_list = []
     run_id = 0
@@ -173,6 +176,10 @@
     step: int,
 ) -> tuple[dict[str, Any], list[dict[str, Any]]]:
     """Collect model and agent data from a model using mesas datacollector."""
+    if not hasattr(model, "datacollector"):
+        raise AttributeError(
+            "The model does not have a datacollector attribute. Please add a DataCollector to your model."
+        )
     dc = model.datacollector
 
     model_data = {param: values[step] for param, values in dc.model_vars.items()}

mesa/model.py

@@ -210,14 +210,13 @@
             tables: tables to collect
 
         """
-        if not hasattr(self, "schedule") or self.schedule is None:
-            raise RuntimeError(
-                "You must initialize the scheduler (self.schedule) before initializing the data collector."
-            )
-        if self.schedule.get_agent_count() == 0:
-            raise RuntimeError(
-                "You must add agents to the scheduler before initializing the data collector."
-            )
+        warnings.warn(
+            "initialize_data_collector() is deprecated. Please use the DataCollector class directly. "
+            "by using `self.datacollector = DataCollector(...)`.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+
         self.datacollector = DataCollector(
             model_reporters=model_reporters,
             agent_reporters=agent_reporters,

tests/test_datacollector.py

@@ -70,7 +70,7 @@ def __init__(self):  # noqa: D107
         self.n = 10
         for i in range(1, self.n + 1):
             self.schedule.add(MockAgent(self, val=i))
-        self.initialize_data_collector(
+        self.datacollector = DataCollector(
             model_reporters={
                 "total_agents": lambda m: m.schedule.get_agent_count(),
                 "model_value": "model_val",
@@ -132,6 +132,7 @@ class TestDataCollector(unittest.TestCase):
     def setUp(self):
         """Create the model and run it a set number of steps."""
         self.model = MockModel()
+        self.model.datacollector.collect(self.model)
         for i in range(7):
             if i == 4:
                 self.model.schedule.remove(self.model.schedule._agents[3])
@@ -234,30 +235,6 @@ def test_exports(self):
             table_df = data_collector.get_table_dataframe("not a real table")
 
 
-class TestDataCollectorInitialization(unittest.TestCase):
-    """Tests for DataCollector initialization."""
-
-    def setUp(self):  # noqa: D102
-        self.model = Model()
-
-    def test_initialize_before_scheduler(self):  # noqa: D102
-        with self.assertRaises(RuntimeError) as cm:
-            self.model.initialize_data_collector()
-        self.assertEqual(
-            str(cm.exception),
-            "You must initialize the scheduler (self.schedule) before initializing the data collector.",
-        )
-
-    def test_initialize_before_agents_added_to_scheduler(self):  # noqa: D102
-        with self.assertRaises(RuntimeError) as cm:
-            self.model.schedule = BaseScheduler(self)
-            self.model.initialize_data_collector()
-        self.assertEqual(
-            str(cm.exception),
-            "You must add agents to the scheduler before initializing the data collector.",
-        )
-
-
 class TestDataCollectorWithAgentTypes(unittest.TestCase):
     """Tests for DataCollector with agent-type-specific reporters."""