Add some historical information

airflow/operators/python_operator.py

@@ -45,7 +45,10 @@ class PythonOperator(BaseOperator):
         For more information on how to use this operator, take a look at the guide:
         :ref:`howto/operator:PythonOperator`
 
+
     :param python_callable: A reference to an object that is callable
+                            The signature of the callable passed to the PythonOperator
+                            is inferred and argument values are always automatically provided.
     :type python_callable: python callable
     :param op_kwargs: a dictionary of keyword arguments that will get unpacked
         in your function

docs/howto/operator/python.rst

@@ -42,6 +42,10 @@ as an argument of the provided callable, the value will be automatically injecte
     :start-after: [START howto_operator_python_kwargs]
     :end-before: [END howto_operator_python_kwargs]
 
+Previously you would set the `provide_context=True` explicitly if you wanted to inject context
+into the function. This has been deprecated since Airflow 2.0 and this is now automatically
+inferred from the signature of the function.
+
 Templating
 ^^^^^^^^^^