Source code for ray.tune.logger.csv

import csv
import logging
from pathlib import Path
from typing import TYPE_CHECKING, Dict, TextIO

from ray.air.constants import EXPR_PROGRESS_FILE
from ray.tune.logger.logger import LoggerCallback
from ray.tune.utils import flatten_dict
from ray.util.annotations import PublicAPI

if TYPE_CHECKING:
    from ray.tune.experiment.trial import Trial  # noqa: F401

logger = logging.getLogger(__name__)




@PublicAPI
class CSVLoggerCallback(LoggerCallback):
    """Logs results to progress.csv under the trial directory.

    Automatically flattens nested dicts in the result dict before writing
    to csv:

        {"a": {"b": 1, "c": 2}} -> {"a/b": 1, "a/c": 2}

    """

    _SAVED_FILE_TEMPLATES = [EXPR_PROGRESS_FILE]

    def __init__(self):
        self._trial_continue: Dict["Trial", bool] = {}
        self._trial_files: Dict["Trial", TextIO] = {}
        self._trial_csv: Dict["Trial", csv.DictWriter] = {}

    def _setup_trial(self, trial: "Trial"):
        if trial in self._trial_files:
            self._trial_files[trial].close()

        # Make sure logdir exists
        trial.init_local_path()
        local_file_path = Path(trial.local_path, EXPR_PROGRESS_FILE)

        # Resume the file from remote storage.
        self._restore_from_remote(EXPR_PROGRESS_FILE, trial)

        self._trial_continue[trial] = (
            local_file_path.exists() and local_file_path.stat().st_size > 0
        )

        self._trial_files[trial] = local_file_path.open("at")
        self._trial_csv[trial] = None

    def log_trial_result(self, iteration: int, trial: "Trial", result: Dict):
        if trial not in self._trial_files:
            self._setup_trial(trial)

        tmp = result.copy()
        tmp.pop("config", None)
        result = flatten_dict(tmp, delimiter="/")

        if not self._trial_csv[trial]:
            self._trial_csv[trial] = csv.DictWriter(
                self._trial_files[trial], result.keys()
            )
            if not self._trial_continue[trial]:
                self._trial_csv[trial].writeheader()

        self._trial_csv[trial].writerow(
            {k: v for k, v in result.items() if k in self._trial_csv[trial].fieldnames}
        )
        self._trial_files[trial].flush()

    def log_trial_end(self, trial: "Trial", failed: bool = False):
        if trial not in self._trial_files:
            return

        del self._trial_csv[trial]
        self._trial_files[trial].close()
        del self._trial_files[trial]