我正在尝试使用streamz来管理图像处理管道。 我正在使用“相机”类模拟相机，并在下面设置了管道。
import time
from skimage.io import imread
from skimage.color import rgb2gray
class Camera(object):
imgs = [imread(f + '.jpg') for f in ['1', '2', '3']]
@staticmethod
def grab_one():
return Camera.imgs[int(time.time()) % 3]
def mc_streamz():
from streamz import Stream
def np2jpeg(np_im):
from six import BytesIO
from PIL import Image
pim = Image.fromarray(np_im)
io = BytesIO()
pim.save(io,format='jpeg')
io.seek(0)
return io.read()
def focusmetric(np_im):
from skimage.filters import laplace
return laplace(np_im).var()
def asjpegframe(b_im):
return b'--frame\r\n'b'Content-Type: image/jpeg\r\n\r\n' + b_im + b'\r\n'
from dask.distributed import Client
client = Client()
source = Stream()
source.map(np2jpeg).map(asjpegframe).sink(print)
source.scatter().map(rgb2gray).map(focusmetric).gather().sink(print)
cam = Camera()
for i in range(10):
source.emit(cam.grab_one())
if __name__ == '__main__':
mc_streamz()
但是，当我运行此程序时，在调用collect（）函数时出现以下异常，我无法理解原因。希望有人能引导我走上正确的道路，谢谢
Traceback (most recent call last):
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/distributed/client.py", line 1438, in _gather
exception = st.exception
AttributeError: exception
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/johndoe/projects/streamz/streamz/core.py", line 1255, in f
result[0] = yield make_coro()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/projects/streamz/streamz/core.py", line 322, in _
result = yield self._emit(x)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 883, in callback
result_list.append(f.result())
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/projects/streamz/streamz/dask.py", line 98, in update
f = yield self._emit(future)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 883, in callback
result_list.append(f.result())
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/projects/streamz/streamz/dask.py", line 123, in update
result = yield client.gather(x, asynchronous=True)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/distributed/client.py", line 1443, in _gather
None)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/six.py", line 693, in reraise
raise value
concurrent.futures._base.CancelledError: focusmetric-42e56666b87e375f3ece9246419ad199
Traceback (most recent call last):
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/distributed/client.py", line 1438, in _gather
exception = st.exception
AttributeError: exception
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "streamprocessing.py", line 83, in <module>
mc_streamz()
File "streamprocessing.py", line 51, in mc_streamz
source.emit(cam.grab_one())
File "/Users/johndoe/projects/streamz/streamz/core.py", line 327, in emit
sync(self.loop, _)
File "/Users/johndoe/projects/streamz/streamz/core.py", line 1267, in sync
six.reraise(*error[0])
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/six.py", line 693, in reraise
raise value
File "/Users/johndoe/projects/streamz/streamz/core.py", line 1255, in f
result[0] = yield make_coro()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/projects/streamz/streamz/core.py", line 322, in _
result = yield self._emit(x)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 883, in callback
result_list.append(f.result())
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/projects/streamz/streamz/dask.py", line 98, in update
f = yield self._emit(future)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 883, in callback
result_list.append(f.result())
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/projects/streamz/streamz/dask.py", line 123, in update
result = yield client.gather(x, asynchronous=True)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1133, in run
value = future.result()
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/tornado/gen.py", line 1141, in run
yielded = self.gen.throw(*exc_info)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/distributed/client.py", line 1443, in _gather
None)
File "/Users/johndoe/anaconda3431/lib/python3.6/site-packages/six.py", line 693, in reraise
raise value
concurrent.futures._base.CancelledError: focusmetric-42e56666b87e375f3ece9246419ad199