class wpilib.DataLogManager

Bases: pybind11_object

Centralized data log that provides automatic data log file management. It automatically cleans up old files when disk space is low and renames the file based either on current date/time or (if available) competition match number. The data file will be saved to a USB flash drive in a folder named “logs” if one is attached, or to /home/lvuser/logs otherwise.

Log files are initially named “FRC_TBD_{random}.wpilog” until the DS connects. After the DS connects, the log file is renamed to “FRC_yyyyMMdd_HHmmss.wpilog” (where the date/time is UTC). If the FMS is connected and provides a match number, the log file is renamed to “FRC_yyyyMMdd_HHmmss_{event}_{match}.wpilog”.

On startup, all existing FRC_TBD log files are deleted. If there is less than 50 MB of free space on the target storage, FRC_ log files are deleted (oldest to newest) until there is 50 MB free OR there are 10 files remaining.

By default, all NetworkTables value changes are stored to the data log.

static getLog() wpiutil._wpiutil.log.DataLog

Get the managed data log (for custom logging). Starts the data log manager if not already started.


data log

static getLogDir() str

Get the log directory.


log directory

static log(message: str) None

Log a message to the “messages” entry. The message is also printed to standard output (followed by a newline).


message – message

static logNetworkTables(enabled: bool) None

Enable or disable logging of NetworkTables data. Note that unlike the network interface for NetworkTables, this will capture every value change. Defaults to enabled.


enabled – true to enable, false to disable

static start(dir: str = '', filename: str = '', period: float = 0.25) None

Start data log manager. The parameters have no effect if the data log manager was already started (e.g. by calling another static function).

  • dir – if not empty, directory to use for data log storage

  • filename – filename to use; if none provided, the filename is automatically generated

  • period – time between automatic flushes to disk, in seconds; this is a time/storage tradeoff

static stop() None

Stop data log manager.