龙卷风框架.TypeError:'Future'对象不可调用

Question

我前段时间开始学习Tornado框架.我遇到了缺乏经验的用户的文档,并检查了asyncio模块文档.所以问题是,我在asyncio中有一些简单的代码:

    import asyncio

    @asyncio.coroutine
    def compute(x, y):
        print("Compute %s + %s ..." % (x, y))
        yield from asyncio.sleep(1.0)
        return x + y


    @asyncio.coroutine
    def print_sum(x, y):
        result = yield from 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()

然后我尝试使用Tornado框架做同样的事情:

from tornado.ioloop import IOLoop
from tornado import gen

@gen.coroutine
def compute(x, y):
   print("Compute %s + %s ..." % (x, y))
   yield gen.sleep(1.0)
   return (x+y)

@gen.coroutine
def print_sum(x, y):
   result = yield compute(x, y)
   print("%s + %s = %s" % (x, y, result))

IOLoop.instance().run_sync(print_sum(1,2))

但遗憾的是Tornado代码引发了这样的异常:

 Compute 1 + 2 ...
Traceback (most recent call last):
  File "tornado_coroutine.py", line 19, in <module>
    IOLoop.instance().run_sync(print_sum(1, 2))
  File "C:\Python34\lib\site-packages\tornado\ioloop.py", line 421, in run_sync
    return future_cell[0].result()
  File "C:\Python34\lib\site-packages\tornado\concurrent.py", line 209, in resul
t
    raise_exc_info(self._exc_info)
  File "<string>", line 3, in raise_exc_info
  File "C:\Python34\lib\site-packages\tornado\ioloop.py", line 402, in run
    result = func()
TypeError: 'Future' object is not callable

在所有协同程序返回其值后,IOLoop可能会尝试创建一个新的"圈"？

Answer 1

run_sync将函数(或其他"可调用")作为参数.您正在调用该函数,然后将结果作为参数.您只需使用lambda以下命令即可创建匿名函数:

IOLoop.instance().run_sync(lambda: print_sum(1,2))