Json serialization of ulab np.array generate syntax error

[zaord]

Hi here,

I have this sample of code :

Code: Select all

result = json.dumps(np.array(range(100),dtype=np.float)).encode('ascii')

print( result)

array = json.loads(str(result, 'ascii'))
print( array)

giving this error :

b'array([0.0, 1.0, 2.0, ..., 597.0, 598.0, 599.0], dtype=float32)'
Traceback (most recent call last):
File "<stdin>", line 20, in <module>
ValueError: syntax error in JSON

Any idea about how I could json to pass numpy array through a serial connection like this git : https://github.com/dhylands/json-ipc

[v923z]

Hi here,

I have this sample of code :

Code: Select all

result = json.dumps(np.array(range(100),dtype=np.float)).encode('ascii')

print( result)

array = json.loads(str(result, 'ascii'))
print( array)

giving this error :

b'array([0.0, 1.0, 2.0, ..., 597.0, 598.0, 599.0], dtype=float32)'
Traceback (most recent call last):
File "<stdin>", line 20, in <module>
ValueError: syntax error in JSON

Any idea about how I could json to pass numpy array through a serial connection like this git : https://github.com/dhylands/json-ipc

I think the problem is caused by the ellipses. You have 100 elements, but only 6 are printed by default.

You have two options. One is to change how the printout behaves, so that all elements are printed: https://micropython-ulab.readthedocs.io ... -printouts

Or you can check out the https://github.com/v923z/micropython-ulab/tree/complex2 branch, which implements the

Code: Select all

.tolist()

array method. https://numpy.org/doc/stable/reference/ ... olist.html This branch will be merged into master in a matter of days.

[zaord]

I did not know but ujson can't handle arrays.

So,Yes i did that, and now i am using bytearray.
Damien Georges solved my problem here :https://github.com/micropython/micropyt ... 1006264156

You need to evaluate the returned data, like this (on the PC):

mes_expr = pyb.exec("print(Grab_Full_Mes(0))")
mes = eval(str(mes_expr, "ascii"))
print(len(mes))
You may also be having issues with flow control and/or a broken Windows USB serial driver. In that case you may need to break up the data into smaller chunks and send them separately.