是的，它会在每次调用时刷新输出。您可以在的源代码中看到StreamHandler：
def flush(self):
"""
Flushes the stream.
"""
self.acquire()
try:
if self.stream and hasattr(self.stream, "flush"):
self.stream.flush()
finally:
self.release()
def emit(self, record):
"""
Emit a record.
If a formatter is specified, it is used to format the record.
The record is then written to the stream with a trailing newline. If
exception information is present, it is formatted using
traceback.print_exception and appended to the stream. If the stream
has an 'encoding' attribute, it is used to determine how to do the
output to the stream.
"""
try:
msg = self.format(record)
stream = self.stream
stream.write(msg)
stream.write(self.terminator)
self.flush() # <---
except (KeyboardInterrupt, SystemExit): #pragma: no cover
raise
except:
self.handleError(record)
我真的不会介意日志记录的性能，至少在分析和发现它是瓶颈之前不会。无论如何，您始终可以创建一个在每次调用时都Handler不会执行的子类（即使如果发生严重异常/解释器崩溃，也可能会丢失大量日志）。flush``emit
602392714
清零编程群