Python 协程总结

import asyncio
@asyncio.coroutine
def hello_world():
    print("Hello World!")
async def hello_world2():
    print("Hello World2!")
print(‘------hello_world------‘)
print(asyncio.iscoroutinefunction(hello_world))
print(‘------hello_world2------‘)
print(asyncio.iscoroutinefunction(hello_world2))
print(‘------event loop------‘)
loop = asyncio.get_event_loop()
# 一直阻塞该函数调用到函数返回
loop.run_until_complete(hello_world())
loop.run_until_complete(hello_world2())
loop.close()

import asyncio
async def compute(x, y):
    print("Compute %s + %s ..." % (x, y))
    await asyncio.sleep(1.0)
    return x + y
async def print_sum(x, y):
    result = await compute(x, y)
    print("%s + %s = %s" % (x, y, result))
loop = asyncio.get_event_loop()
loop.run_until_complete(print_sum(1, 2))
loop.close()

import asyncio
async def slow_operation(future):
    await asyncio.sleep(1)  # 睡眠
    future.set_result(‘Future is done!‘)  # future设置结果
loop = asyncio.get_event_loop()
future = asyncio.Future()  # 创建future对象
asyncio.ensure_future(slow_operation(future))  # 创建任务
loop.run_until_complete(future)  # 阻塞直到future执行完才停止事件
print(future.result())
loop.close()

import asyncio
async def slow_operation(future):
    await asyncio.sleep(1)
    future.set_result(‘Future is done!‘)
def got_result(future):
    print(future.result())
    loop.stop()  # 关闭事件
loop = asyncio.get_event_loop()
future = asyncio.Future()
asyncio.ensure_future(slow_operation(future))
future.add_done_callback(got_result)  # future执行完毕就执行该回调
try:
    loop.run_forever()
finally:
    loop.close()

import asyncio
async def factorial(name, number):
    f = 1
    for i in range(2, number+1):
        print("Task %s: Compute factorial(%s)..." % (name, i))
        await asyncio.sleep(1)
        f *= i
    print("Task %s: factorial(%s) = %s" % (name, number, f))
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.gather(
    factorial("A", 2),
    factorial("B", 3),
    factorial("C", 4),
))
loop.close()