PythonShell is not a constructor (v1.0.4)

[surfaceowl]

After upgrading from "python-shell": "0.5.0" to "python-shell": "1.0.4", a previously working link that invokes a python script now returns the error "PythonShell is not a constructor"

The previously working code included:

...
const PythonShell = require("python-shell");
...
let pyshell = new PythonShell(script, options);

I noticed that this recent commit mentions constructors, but does not seem to change the API. There is also this change in the Readme.md

... but the examples below in same the Readme appear to be the same as before v1.0.4.

Should I configure something differently, or is this a potential bug?

[Almenon]

You need the below code:

const {PythonShell} = require("python-shell");

Does that work?

[Almenon]

I already made a note of it in the github readme but if you confirm that {PythonShell} works I'll release 1.0.5 with updated readme to npm

[surfaceowl]

@Almenon -- Yes! adding the curly brackets fixed it -- and thank you very much for such a quick reply - greatly appreciated.

[shayfer]

Adding the curly brackets produces a new error. Thanks for any help!

SyntaxError: Unexpected token T in JSON at position 0
at JSON.parse ()
at PythonShell.asJson (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:350:21)
at /home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:302:42
at Array.forEach ()
at PythonShell.recieveInternal (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:298:15)
at PythonShell.receiveStderr (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:282:21)
at Socket. (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:100:18)
at emitOne (events.js:116:13)
at Socket.emit (events.js:211:7)
at addChunk (_stream_readable.js:263:12)
{ Error: ImportError: No module named 'cv2'
at PythonShell.parseError (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:232:21)
at terminateIfNeeded (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:121:32)
at ChildProcess. (/home/pi/MagicMirror/modules/MMM-Motion-Detection/node_modules/python-shell/index.js:113:13)
at emitTwo (events.js:126:13)
at ChildProcess.emit (events.js:214:7)
at Process.ChildProcess._handle.onexit (internal/child_process.js:198:12)
----- Python Traceback -----
File "modules/MMM-Motion-Detection/motiondetection/motiondetection.py", line 19, in
import cv2
traceback: 'Traceback (most recent call last):\n File "modules/MMM-Motion-Detection/motiondetection/motiondetection.py", line 19, in \n import cv2\nImportError: No module named 'cv2'\n',
executable: 'python3',
options: null,
script: 'modules/MMM-Motion-Detection/motiondetection/motiondetection.py',
args:
[ '{"useUSBCam":false,"interval":1,"motionStopDelay":120,"detectionThreshold":1000,"turnOffDisplay":true}' ],
exitCode: 1 }

[Almenon]

You got a python error - you tried importing cv2 but it could not be found.

[shayfer]

What is the next step do you think? I did a search within the modules/MMM-Motion-Detection/motiondetection folder and there is no cv2. I also tried a search from the root for cv2 files.
Python is installed via sudo apt-get install libopencv-dev python-opencv

Thanks!

[Almenon]

What does pip freeze result in? Maybe you need to install cv2 via pip?

…

On Fri, Oct 26, 2018, 8:40 AM shayfer ***@***.***> wrote: What is the next step do you think? I did a search within the modules/MMM-Motion-Detection/motiondetection folder and there is no cv2. I also tried a search from the root for cv2 files. Python is installed via sudo apt-get install libopencv-dev python-opencv Thanks! — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#154 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AMeZhYpBhwwIOc8BqIO6ysh3RYuQpEYgks5uoyzzgaJpZM4WvUxH> .

[surfaceowl]

I think @Almenon has made a good suggestion - seems like cv2 is missing something, perhaps one of the related packages like: opencv-contrib-python or pip install opencv-contrib-python-headless (per
https://pypi.org/project/opencv-python/)

Also found this stackoverflow guidance: https://stackoverflow.com/questions/10417108/what-is-different-between-all-these-opencv-python-interfaces

[shayfer]

Good call! I tried installing via pip install opencv-python. That results in Pip fails with Could not find a version that satisfies the requirement ... I next tried pip install --upgrade pip which did result in a successful installation. I am getting the same error message now. I did reboot after the install and I would guess the order of installing PIP after Python shouldn't matter?

[surfaceowl]

correct, order of installing pip after python does not matter. Now that pip is upgraded, you should check to see if all the packages needed for your setup are installed (per this site: https://pypi.org/project/opencv-python/) .... some important notes there:

1. IF you manually installed opencv before trying with python, remove it
2. There are four different options to install, and you should install only one of them based on your setup.
3. Also, recommend that after about on continuous output #2 is done, before trying your code again -- check if cv2 is properly installed by using python from the terminal and trying to import cv2. (so from terminal command is python or python3 depending on your install, then when at the python prompt - type import cv2. if that works, you should be good to go. exit python prompt with exit()

[shayfer]

Ok. I did an uninstall to make sure I did not have different packages. I installed with an update again.

Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Requirement already up-to-date: pip in /usr/local/lib/python2.7/dist-packages (18.1)

Also I see on the referenced webpage that for newest versions of Raspian it already has it installed. I did verify from https://www.piwheels.org/ checking the pip.conf.

I did try the import. No error message and it goes to the next line which makes me think it's successful?
pi@MagicMirror:~/MagicMirror/modules/MMM-Motion-Detection $ python
Python 2.7.13 (default, Sep 26 2018, 18:42:22)
[GCC 6.3.0 20170516] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import cv2

I am also thinking maybe just another total fresh install and try it all over again?

Thanks again for your help!