All possible states that a Task Instance can be in. Note that None is also allowed, so always use this in a type hint with Optional.
REMOVED (value: 'removed')
SCHEDULED (value: 'scheduled')
QUEUED (value: 'queued')
RUNNING (value: 'running')
SUCCESS (value: 'success')
RESTARTING (value: 'restarting')
FAILED (value: 'failed')
UP_FOR_RETRY (value: 'up_for_retry')
UP_FOR_RESCHEDULE (value: 'up_for_reschedule')
UPSTREAM_FAILED (value: 'upstream_failed')
SKIPPED (value: 'skipped')
DEFERRED (value: 'deferred')