#917 - Overhauled transaction and mean reward writing.

- Separated out learning outputs from evaluation outputs

src/primaite/utils/session_output_writer.py

@@ -0,0 +1,73 @@
+import csv
+from logging import Logger
+from typing import List, Final, IO, Union, Tuple
+from typing import TYPE_CHECKING
+
+from primaite import getLogger
+from primaite.transactions.transaction import Transaction
+
+if TYPE_CHECKING:
+    from primaite.environment.primaite_env import Primaite
+
+_LOGGER: Logger = getLogger(__name__)
+
+
+class SessionOutputWriter:
+    _AV_REWARD_PER_EPISODE_HEADER: Final[List[str]] = [
+        "Episode", "Average Reward"
+    ]
+
+    def __init__(
+            self,
+            env: "Primaite",
+            transaction_writer: bool = False,
+            learning_session: bool = True
+    ):
+        self._env = env
+        self.transaction_writer = transaction_writer
+        self.learning_session = learning_session
+
+        if self.transaction_writer:
+            fn = f"all_transactions_{self._env.timestamp_str}.csv"
+        else:
+            fn = f"average_reward_per_episode_{self._env.timestamp_str}.csv"
+
+        if self.learning_session:
+            self._csv_file_path = self._env.session_path / "learning" / fn
+        else:
+            self._csv_file_path = self._env.session_path / "evaluation" / fn
+
+        self._csv_file_path.parent.mkdir(exist_ok=True, parents=True)
+
+        self._csv_file = None
+        self._csv_writer = None
+
+        self._first_write: bool = True
+
+    def _init_csv_writer(self):
+        self._csv_file = open(
+            self._csv_file_path, "w", encoding="UTF8", newline=""
+        )
+
+        self._csv_writer = csv.writer(self._csv_file)
+
+    def __del__(self):
+        if self._csv_file:
+            self._csv_file.close()
+            _LOGGER.info(f"Finished writing file: {self._csv_file_path}")
+
+    def write(
+            self,
+            data: Union[Tuple, Transaction]
+    ):
+        if isinstance(data, Transaction):
+            header, data = data.as_csv_data()
+        else:
+            header = self._AV_REWARD_PER_EPISODE_HEADER
+
+        if self._first_write:
+            self._init_csv_writer()
+            self._csv_writer.writerow(header)
+            self._first_write = False
+
+        self._csv_writer.writerow(data)