TypeError: object of type 'NoneType' has no len()

[itsmespydy]

Mycode :
import sys
import soundfile
import os
import pyaudio
sys.path.append(r'C:\Users\Mashud A Talukdar\AppData\Local\Programs\Python\Python36\Lib\site-packages\porcupine\binding\python')
from porcupine import Porcupine

library_path= 'C:\Users\Mashud A Talukdar\AppData\Local\Programs\Python\Python36\Lib\site-packages\porcupine\lib\windows\amd64\libpv_porcupine.dll'
model_file_path='C:\Users\Mashud A Talukdar\AppData\Local\Programs\Python\Python36\Lib\site-packages\porcupine\lib\common\porcupine_params.pv'
keyword_file_paths=['C:\Users\Mashud A Talukdar\AppData\Local\Programs\Python\Python36\Lib\site-packages\porcupine\resources\keyword_files\windows\alexa_windows.ppn']
sensitivities=[0.5]
handle = Porcupine(library_path, model_file_path, keyword_file_paths=keyword_file_paths, sensitivities=sensitivities)
def get_next_audio_frame():
pass

while True:
pcm = get_next_audio_frame()
keyword_index = handle.process(pcm)
if keyword_index >= 0:
# detection event logic/callback
pass

output :
File "c:/Users/Mashud A Talukdar/Desktop/Python/test.py", line 18, in
keyword_index = handle.process(pcm)
File "C:\Users\Mashud A Talukdar\AppData\Local\Programs\Python\Python36\lib\site-packages\porcupine\binding\python\porcupine.py", line 154, in process
status = self.process_func(self._handle, (c_short * len(pcm))(*pcm), byref(result))
TypeError: object of type 'NoneType' has no len()

please help me sir
i am working on college project and i need a hotword detection in my python project to start my project

[kenarsa]

you need to implement "def get_next_audio_frame()" yourself for you platform. it is returning nothing now.

[justUmen]

I think the SDK python README should have at least a workable example that everybody can use/edit easily.
Like this one for example.

#!/usr/bin/env python3
import struct
import pyaudio
import pvporcupine
print(pvporcupine.KEYWORDS)

porcupine = None
pa = None
audio_stream = None

try:
    porcupine = pvporcupine.create(keywords=["picovoice", "blueberry"])

    pa = pyaudio.PyAudio()

    audio_stream = pa.open(
                    rate=porcupine.sample_rate,
                    channels=1,
                    format=pyaudio.paInt16,
                    input=True,
                    frames_per_buffer=porcupine.frame_length)

    while True:
        pcm = audio_stream.read(porcupine.frame_length)
        pcm = struct.unpack_from("h" * porcupine.frame_length, pcm)

        keyword_index = porcupine.process(pcm)

        if keyword_index >= 0:
            print("Hotword Detected")
finally:
    if porcupine is not None:
        porcupine.delete()

    if audio_stream is not None:
        audio_stream.close()

    if pa is not None:
            pa.terminate()

[kenarsa]

https://github.com/Picovoice/porcupine/blob/master/demo/python/porcupine_demo_mic.py