TypeError:LoadLibrary() 参数 1 必须是 str，而不是 None

Question

I have been trying to learn SpeechRecognition in python, so I decided working with code provided by Picovoice Github, When I tried running the script in Colab it works fine. But it fails to do so when I run in my desktop.

C:\Users\ELCOT\Downloads\cheetah-master\cheetah-master>python demo/python/cheetah_demo.py --audio_paths resources/audio_samples/test.wav --license_path license_cta_v1.2.0_linux_expires_2020-08-27.lic
Traceback (most recent call last):
  File "demo/python/cheetah_demo.py", line 61, in <module>
    license_path=args.license_path)
  File "demo/python\../../binding/python\cheetah.py", line 63, in __init__
    self._libc = CDLL(find_library('c'))
  File "C:\Python 36\lib\ctypes\__init__.py", line 348, in __init__
    self._handle = _dlopen(self._name, mode)
TypeError: LoadLibrary() argument 1 must be str, not None

I tried with Anaconda too, it shows me the same error. I am stuck in this for couple of week, please help. (I am using python 3.6.8 X64 in win 10) Will completely reinstalling anaconda do the work?

Answer 1

The error you experience comes from poor code you got from GitHub that does no error checking.

The relevant trace is:

self._libc = CDLL(find_library('c'))
self._handle = _dlopen(self._name, mode)
LoadLibrary()

It appears the find_library call could not locate the C library and so returned the value None .

That value is then used in the dlopen call which underneath uses the LoadLibrary function of the Windows API. However, this now uses an unknown name or empty parameter None and consequently fails.

On https://docs.python.org/2.5/lib/ctypes-finding-shared-libraries.html :

find_library(name) : Try to find a library and return a pathname.

On Windows, find_library searches along the system search path, and returns the full pathname, but since there is no predefined naming scheme a call like find_library("c") will fail and return None.

So a solution could be to add the location of the library (probably libc.lib ) to the PATH environment variable.

Answer 2

You can't run the free version of Cheetah on Windows, it simply isn't supported. The code in the GitHub repository only supports Linux.

The fourth bullet point in the README is as follows (emphasis mine):

• cross-platform. Linux (x86_64), Mac (x86_64), Windows (x86_64), web browsers, Android, iOS, Raspberry Pi, and BeagleBone are supported. Linux (x86_64) is available for personal and non-commercial use free of charge. Other platforms are only available under the commercial license.