quantlab.utils.progress.ProgressReporter

class quantlab.utils.progress.ProgressReporter

Bases: ABC

Abstract destination for progress events.

Subclasses implement emit. The loop calls it once per event and ignores the return value, so a reporter cannot stop a run. That is intentional: stopping goes through CancelToken, so a reporter that only wants to log can never halt a multi-hour download by accident.

Examples

>>> class PrintReporter(ProgressReporter):
...     def emit(self, event: ProgressEvent) -> None:
...         print(event.kind, event.completed, event.total)

close()

Release any resource emit opened. The default does nothing.

Examples

>>> class FileReporter(ProgressReporter):
...     def __init__(self, path):
...         self._handle = open(path, "a")
...     def emit(self, event: ProgressEvent) -> None:
...         print(event.kind, file=self._handle)
...     def close(self) -> None:
...         self._handle.close()

abstractmethod emit(event)

Receive one event.

Implementations should not raise. If one does, the calling loop logs the exception and carries on, so a bug in reporting cannot end a long download.

Parameters:

eventProgressEvent

The event to handle.

Examples

>>> class ListReporter(ProgressReporter):
...     def __init__(self):
...         self.events = []
...     def emit(self, event: ProgressEvent) -> None:
...         self.events.append(event)