CODEWITHSUNDEEP
pythontornadobinary-data
AME
AME

Reputation: 2609

How do I serve a binary data from Tornado?

I have a numpy array, that I want to serve using Tornado, but when I try to write it using self.write(my_np_array) I just get an AssertionErrror.

What am I doing wrong?

File "server.py", line 28, in get
self.write(values)
File "/usr/lib/python2.7/site-packages/tornado/web.py", line 468, in write
chunk = utf8(chunk)
File "/usr/lib/python2.7/site-packages/tornado/escape.py", line 160, in utf8
assert isinstance(value, unicode)

Upvotes: 1

Views: 2027

Answers (1)

Codetoffel
Codetoffel

Reputation: 2793

Not exactly sure what your goal is, but if you want to get a string representation of the object you can do

self.write(str(your_object))

If you want to serve the numpy array as a python object in order to use it on a different client you need to pickle the object first

import pickle
self.write(pickle.dumps(your_object))

the object can then be retrieved with

your_object = pickle.loads(sent_object)

Keep in mind that it is dangerous to unpickle objects from an untrusted source as it can lead to malicious code execution.

Edit:

If you want to transfer a numpy array and use it within javascript you don't need a binary representation.

Just convert the numpy array to a list

your_numpy_list = your_numpy_object.tolist()

and convert it to json

import json
self.write(json.dumps(your_numpy_list))

at the javascript side you just parse the result string

var result = JSON.parse(resultString)

and create the typed array from it

var typedResult = new Float32Array(result)

voila!

Upvotes: 1

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