问题描述
使用下面的代码,我尝试使用asyncio启动2个无限循环:
async def do_job_1():
while True :
print('do_job_1')
await asyncio.sleep(5)
async def do_job_2():
while True :
print('do_job_2')
await asyncio.sleep(5)
if __name__ == '__main__':
asyncio.run(do_job_1())
asyncio.run(do_job_2())
do_job_1
阻止do_job_2
,因为do_job_2
从不打印do_job_1。我犯了什么错误?
最终我正在尝试转换kafka消费者代码:
from confluent_kafka import Consumer,KafkaError
settings = {
'bootstrap.servers': 'localhost:9092','group.id': 'mygroup','client.id': 'client-1','enable.auto.commit': True,'session.timeout.ms': 6000,'default.topic.config': {'auto.offset.reset': 'smallest'}
}
c = Consumer(settings)
c.subscribe(['mytopic'])
try:
while True:
msg = c.poll(0.1)
if msg is None:
continue
elif not msg.error():
print('Received message: {0}'.format(msg.value()))
elif msg.error().code() == KafkaError._PARTITION_EOF:
print('End of partition reached {0}/{1}'
.format(msg.topic(),msg.partition()))
else:
print('Error occured: {0}'.format(msg.error().str()))
except KeyboardInterrupt:
pass
finally:
c.close()
从https://www.confluent.io/blog/introduction-to-apache-kafka-for-python-programmers中提取的是并发的,因此我可以并行处理Kafka消息。
解决方法
来自help(asyncio.run)
:
应将其用作asyncio程序的主要入口,理想情况下应仅调用一次。
但是您可以使用asyncio.gather
来加入任务:
import asyncio
async def do_job_1():
while True :
print('do_job_1')
await asyncio.sleep(5)
async def do_job_2():
while True :
print('do_job_2')
await asyncio.sleep(5)
async def main():
await asyncio.gather(do_job_1(),do_job_2())
if __name__ == '__main__':
asyncio.run(main())