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prefect.logging

get_logger cached

Get a prefect logger. These loggers are intended for internal use within the prefect package.

See get_run_logger for retrieving loggers for use within task or flow runs. By default, only run-related loggers are connected to the APILogHandler.

Source code in prefect/logging/loggers.py 
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@lru_cache()
def get_logger(name: str = None) -> logging.Logger:
    """
    Get a `prefect` logger. These loggers are intended for internal use within the
    `prefect` package.

    See `get_run_logger` for retrieving loggers for use within task or flow runs.
    By default, only run-related loggers are connected to the `APILogHandler`.
    """

    parent_logger = logging.getLogger("prefect")

    if name:
        # Append the name if given but allow explicit full names e.g. "prefect.test"
        # should not become "prefect.prefect.test"
        if not name.startswith(parent_logger.name + "."):
            logger = parent_logger.getChild(name)
        else:
            logger = logging.getLogger(name)
    else:
        logger = parent_logger

    return logger

get_run_logger

Get a Prefect logger for the current task run or flow run.

The logger will be named either prefect.task_runs or prefect.flow_runs. Contextual data about the run will be attached to the log records.

These loggers are connected to the APILogHandler by default to send log records to the API.

Parameters:

Name Type Description Default
context RunContext

A specific context may be provided as an override. By default, the context is inferred from global state and this should not be needed.

 None
**kwargs str

Additional keyword arguments will be attached to the log records in addition to the run metadata

 {}

Raises:

Type Description
RuntimeError

If no context can be found
Source code in prefect/logging/loggers.py 
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def get_run_logger(
    context: "RunContext" = None, **kwargs: str
) -> Union[logging.Logger, logging.LoggerAdapter]:
    """
    Get a Prefect logger for the current task run or flow run.

    The logger will be named either `prefect.task_runs` or `prefect.flow_runs`.
    Contextual data about the run will be attached to the log records.

    These loggers are connected to the `APILogHandler` by default to send log records to
    the API.

    Arguments:
        context: A specific context may be provided as an override. By default, the
            context is inferred from global state and this should not be needed.
        **kwargs: Additional keyword arguments will be attached to the log records in
            addition to the run metadata

    Raises:
        RuntimeError: If no context can be found
    """
    # Check for existing contexts
    task_run_context = prefect.context.TaskRunContext.get()
    flow_run_context = prefect.context.FlowRunContext.get()

    # Apply the context override
    if context:
        if isinstance(context, prefect.context.FlowRunContext):
            flow_run_context = context
        elif isinstance(context, prefect.context.TaskRunContext):
            task_run_context = context
        else:
            raise TypeError(
                f"Received unexpected type {type(context).__name__!r} for context. "
                "Expected one of 'None', 'FlowRunContext', or 'TaskRunContext'."
            )

    # Determine if this is a task or flow run logger
    if task_run_context:
        logger = task_run_logger(
            task_run=task_run_context.task_run,
            task=task_run_context.task,
            flow_run=flow_run_context.flow_run if flow_run_context else None,
            flow=flow_run_context.flow if flow_run_context else None,
            **kwargs,
        )
    elif flow_run_context:
        logger = flow_run_logger(
            flow_run=flow_run_context.flow_run, flow=flow_run_context.flow, **kwargs
        )
    elif (
        get_logger("prefect.flow_run").disabled
        and get_logger("prefect.task_run").disabled
    ):
        logger = logging.getLogger("null")
    else:
        raise MissingContextError("There is no active flow or task run context.")

    return logger