Develop Reference

ModuleNotFoundError: No module named '_brotli' when trying to install dash

I try to install dash on a mac OS, and I have the following error when running 'import dash' on a python script:
Traceback (most recent call last):
File "app.py", line 16, in <module>
import dash
File "/Users/manuel/Library/Python/3.9/lib/python/site-packages/dash/__init__.py", line 5, in <module>
from .dash import Dash, no_update # noqa: F401,E402
File "/Users/manuel/Library/Python/3.9/lib/python/site-packages/dash/dash.py", line 17, in <module>
from flask_compress import Compress
File "/Users/manuel/Library/Python/3.9/lib/python/site-packages/flask_compress/__init__.py", line 1, in <module>
from .flask_compress import Compress
File "/Users/manuel/Library/Python/3.9/lib/python/site-packages/flask_compress/flask_compress.py", line 14, in <module>
import brotli
File "/Users/manuel/Library/Python/3.9/lib/python/site-packages/brotli.py", line 8, in <module>
import _brotli
ModuleNotFoundError: No module named '_brotli'
I can't figure it out what is the problem. I use python 3.7. I saw on the internet a similar issue on windows, but not on mac. I would be really grateful if you could help me.

You seem to have a broken installation of the brotli module (missing its native code component _brotli).
Try uninstalling it with pip uninstall brotli, then reinstall it; pip install brotli.
Going forward, I would heavily recommend you learn and use virtualenvs instead of installing everything into your Python's site-packages.

After uninstalling and installing again brotli it worked! Moreover, working in virtual environments is really more appropriate. Thank you a lot, AKX.

ImportError: No module named gobject

I installed ros1 and created a catkin workspace. Inside the src folder I cloned a ros package "executive_smach_visualization". But when I try to run it with the following command I am getting an error.
rosrun smach_viewer smach_viewer.py
Traceback:
wxversion 2.8 is not installed, installed versions are ['3.0-gtk3']
Traceback (most recent call last):
File "/home/developer/catkin_ws/src/executive_smach_visualization/smach_viewer/scripts/smach_viewer.py", line 77, in <module>
from smach_viewer import xdot
File "/home/developer/catkin_ws/src/executive_smach_visualization/smach_viewer/src/smach_viewer/xdot/__init__.py", line 1, in <module>
import wxxdot
File "/home/developer/catkin_ws/src/executive_smach_visualization/smach_viewer/src/smach_viewer/xdot/wxxdot.py", line 22, in <module>
from xdot import *
File "/home/developer/catkin_ws/src/executive_smach_visualization/smach_viewer/src/smach_viewer/xdot/xdot.py", line 34, in <module>
import gobject
ImportError: No module named gobject
I have already tried following:
1) Installed goobject using pip
2) cloned gobject from git to src folder of catkin_ws, catkin_make and setup.bash
What could be the problem? Please let me know if I am missing any important input. Thanks in advance.

This issue occurs if there is different version of ros, python and so on.
It seems package is a little bit outdated.
Edit:
After downloading package and when building your working environment, use:
catkin_make -DPYTHON_EXECUTABLE=/usr/bin/python2 -DPYTHON_INCLUDE_DIR=/usr/include/python2.7 -DPYTHON_LIBRARY=/usr/lib/libpython2.7.so
Please refer to 1.5 section (User configuration) of this guide

ImportError: cannot import name QtWebKit when using PySide

I am trying to get my old project clipmanager building and I am encountering the following error:
/home/user/.virtualenvs/clipmanager27/bin/python /home/user/development/clipmanager/clipmanager/app.py
Traceback (most recent call last):
File "/home/user/development/clipmanager/clipmanager/app.py", line 15, in <module>
from mainwindow import MainWindow
File "/home/user/development/clipmanager/clipmanager/mainwindow.py", line 12, in <module>
import dialogs
File "/home/user/development/clipmanager/clipmanager/dialogs.py", line 8, in <module>
from PySide import QtWebKit
ImportError: cannot import name QtWebKit
Process finished with exit code 1
I installed Pyside with pip install pyside. I do not even see QtWebKit.so in the site packages folder /home/user/.virtualenvs/clipmanager27/lib/python2.7/site-packages/PySide:
Did it get removed due to licensing?

For Arch Linux, install qt4 and also qtwebkit before installing PySide.

Module method showing strange behavior

Guys I'm facing a problem on using this module which i install from pip currently my OS is Windows python36 64bit version is install. When i'm using and try to import this module
from drawtree import draw_level_order
draw_level_order('{3,9,20,#,#,15,7}')
Why python giving strange errors like this
Traceback (most recent call last):
File "C:/Users/Root/PycharmProjects/untitled/src/Test.py", line 1, in <module>
from drawtree import draw_level_order
File "C:\Python36-64\lib\site-packages\drawtree\__init__.py", line 7, in <module>
from drawtree import draw_bst, draw_random_bst, draw_level_order
ImportError: cannot import name 'draw_bst'

The version of drawtree on PyPI is not currently compatible with Python 3. There's a Python 3-compatible version on Github, if you really want to use drawtree on Python 3.

Python igraph import error on Windows

I've installed igraph form .whl file using pip install. When I was trying to test the correctness of installation
import igraph.test
igraph.test.test()
I got this error:
Traceback (most recent call last):
File "D:/Nauka/Praca-inzynierska/Barabasi-Albert.py", line 4, in <module>
import igraph.test
File "D:\Programy\Python 3.5\lib\site-packages\igraph\__init__.py", line 34, in <module>
from igraph._igraph import *
ImportError: No module named 'igraph._igraph'
(the same error pops out if I'm trying to import igraph not igraph.test).
I've tried adding path (I don't know if this is rigth):
import sys
sys.path.append ("D:/Programy/Python 3.5/Lib/site-packages/igraph")
but it didn't work.
One thing I discovered is that if I delete "__init__" file from igraph folder I can import igraph without error, but it doesn't work for igraph.test.
If it's relevant I have Python 2.7 installed on my machine alongside Python 3.5.
Thank you in advance for any help.