Develop Reference

Why aren't transformers imported in Python?

I want to import transformers in jupyter notebook but I get the following error. What is the reason for this error? My Python version is 3.8
ImportError: cannot import name 'TypeAlias' from 'typing_extensions'
I also updated the typing-extensions library version, but the problem was not resolved

You could try
pip install typing-extensions --upgrade

maybe the probelm is the version of datasets package:
pip install datasets==1.15

TypeAlias is available from python version 3.10.
You should upgrade your python version to avoid the error.

Python module ortools apparently installs incompletely

I am trying to set up ortools on my Mac.
I installed via pip install ortools. I can verify that the package installed successfully.
conda list | grep ortools
WARNING: The conda.compat module is deprecated and will be removed in a future release.
ortools 7.1.6720 pypi_0 pypi
When I try to use the library, it looks like there are missing functions. I followed along with the example here:
https://developers.google.com/optimization/introduction/python
This returns an error:
from __future__ import print_function
from ortools.linear_solver import pywraplp
Traceback (most recent call last):
File "simple_ortools_example.py", line 2, in <module>
from ortools.linear_solver import pywraplp
ImportError: No module named ortools.linear_solver
I can import the module otherwise and look at the functions interactively:
>>> ortools.__
ortools.__cached__ ortools.__gt__( ortools.__path__
ortools.__class__( ortools.__hash__( ortools.__reduce__(
ortools.__delattr__( ortools.__init__( ortools.__reduce_ex__(
ortools.__dict__ ortools.__init_subclass__( ortools.__repr__(
ortools.__dir__( ortools.__le__( ortools.__setattr__(
ortools.__doc__ ortools.__loader__ ortools.__sizeof__(
ortools.__eq__( ortools.__lt__( ortools.__spec__
ortools.__file__ ortools.__name__ ortools.__str__(
ortools.__format__( ortools.__ne__( ortools.__subclasshook__(
ortools.__ge__( ortools.__new__( ortools.__version__
ortools.__getattribute__( ortools.__package__
I just used tab complete here to see what was available. Sure enough there is no linear_solver attached to the ortools module.
I'm a bit at a loss as to what to try next. Any advice would be apreciated.

I downgraded to an earlier version which solves the problem.
pip install ortools==6.7.4973

I faced the same issue today on Windows. Figured out that it is usually caused due to missing Microsoft Visual Studio 20** redistributables c++ (see here).
This is how I solved it (Python 3.7.6, ortools Version: 7.5.*).
Got the latest Microsoft Visual Studio 20** redistributables c++ from https://support.microsoft.com/en-my/help/2977003/the-latest-supported-visual-c
downloads
Installed it and Restarted the computer.
Uninstall the ortools 'python -m pip uninstall ortools'
Install back the ortools 'python -m pip install --user ortools'
Validated installation with python -c "from ortools.linear_solver import pywraplp"

Python wkhtmltopdf can't import module

I am using Python version 3.6, Django version 1.9 and wkhtmltopdf version 0.2. My Python is not GCC it's Anaconda3.
When running my project which uses wkhtmltopdf, following error will be thrown:
from main import WKhtmlToPdf, wkhtmltopd
ModuleNotFoundError: No module named 'main'
This is how I imported the wkhtmltopdf:
import pdfkit
from wkhtmltopdf.views import PDFTemplateView

Yes i got the answer. This error occurred because i didn't installed django-wkhtmltopdf.
installed >> `pip install django-wkhtmltopdf
I hope this answer will help to resolve the similar error.

after installing pdfkit with following command and pointing python version 3.8, i was able to get pdfkit working on mac
pip3 install pdfkit

Importing opencv and getting numpy.core.multiarray failed to import

Trying to install OpenCV and running into an issue where attempting to import cv2 results in this output -
RuntimeError: module compiled against API version 9 but this version of numpy is 7
Traceback (most recent call last):
File "<pyshell#4>", line 1, in <module>
import cv2
ImportError: numpy.core.multiarray failed to import
I'm running on Windows 7 x64, Python v 2.7.9
Thanks!

The error is telling you that you have an out of date version of numpy. If you used pip to install things you can simply run pip install numpy -U, or download the appropriate version from their website.

In case
pip install -U numpy
doesn't work (even with sudo), you may want to make sure you're using the right version of numpy. I had the same "numpy.core.multiarray failed to import" issue, but it was because I had 1.6 installed for the version of Python I was using, even though I kept installing 1.8 and assumed it was installing in the right directory.
I found the bad numpy version by using the following command in my Mac terminal:
python -c "import numpy;print numpy.version;print numpy.file";
This command gave me the version and location of numpy that I was using (turned out it was 1.6.2). I went to this location and manually replaced it with the numpy folder for 1.8, which resolved my "numpy.core.multiarray failed to import" issue. Hopefully someone finds this useful!

I had a similar problem and I solved it by downgrading my numpy version.
What I did was:
pip install opencv-python
pip uninstall numpy
pip install numpy=1.18
This has worked for me using
Python 3.7
opencv-python 4.4.0.46
numpy 1.18.0

linux: sudo apt-get install python-numpy

if you are using ubuntu bionic beaver then try running: sudo apt-get install python-numpy
had the same issue, resolve by running the above command.
Hope it helps

In your environment you can try this command:
conda uninstall numpy
conda install -c conda-forge numpy

I use Python 3.7 # RPI 4.
For opencv to install properly I had to install the listed libraries below.
(Not every package was actually installed, after request)
Regarding Numpy, I think one should stick to the latest version.
For me what worked is to uninstall the existing version 1.16.2 and stick with the current stable 1.21.2.
Stackoverflow topic at missing libraries here: ImportError: libcblas.so.3: cannot open shared object file: No such file or directory.

Problems importing python-Xlib

I installed a new module and it appears as if one of its dependencies was not already installed. The module is called Xlib.display.
Here is the error message I received:
from Xlib.display import Display
ImportError: No module named Xlib.display
Where can I find this module that I am apparently lacking? Google yielded no leads.
"Edit: I already have that sourceforge module downloaded but I still get the same results.

Please try.
This shall install Xlib
sudo apt-get install python-xlib
Then you can check
>>from Xlib.display import Display
To install PyMouse if you want to control and capture mouse events please use:
sudo easy_install https://github.com/pepijndevos/PyMouse/zipball/master

Below worked for me!
pip install python3_xlib
I have also used pyuserinput for automation which requires this.

I was having the same problem, but the solutions above didn't work for me. Since I had installed python through the anaconda package, when I used:
sudo apt-get install python-xlib
Xlib was still undetectable by python2. The solution in my case was to use:
anaconda search -t conda python-xlib
Then find the package from the anaconda api, mine was erik/python-xlib. Install it using:
conda install --channel https://conda.anaconda.org/erik python-xlib
Then it worked.

On Debian systems install python-xlib.
On other systems there's a high probability that the package carries the same name.

I don't think the Xlib library works in Python 3.
Source:
Requirements
The Python X Library requires Python 1.5.2 or newer. It has been tested to various extents with Python 1.5.2 and 2.0 through 2.6.

I honestly cant explain why this works... but here is the command that got it working for me.
sudo apt-get install python3-xlib
Should not work because xlib apparently does not work with python 3.x, but everything installed alright, so I'm not complaining!

I was looking for the same answer, however after some more digging it seems that XCB (X protocol C-language Binding) will obsolete Xlib in general. From the XCB website:
The X protocol C-language Binding (XCB) is a replacement for Xlib featuring a small footprint, latency hiding, direct access to the protocol, improved threading support, and extensibility.
Fortunately there are python bindings available as python-xpyb in apt or xpyb on PyPi. I've not gotten that far in my project so I haven't tested if this works with Python3, but this is probably the way to go and the proper place to file any Python3 support bugs if necessary.

Scenario:
I was trying to use screenshot functionalities of pyautogui package. I was getting this error:
Traceback (most recent call last):
File "test_screenshot.py", line 1, in <module>
import pyautogui
File ".../miniconda3/envs/myenv/lib/python3.7/site-packages/pyautogui/__init__.py", line 152, in <module>
from . import _pyautogui_x11 as platformModule
File ".../miniconda3/envs/myenv/lib/python3.7/site-packages/pyautogui/_pyautogui_x11.py", line 7, in <module>
from Xlib.display import Display
ModuleNotFoundError: No module named 'Xlib'
Python code (test_screenshot.py):
import pyautogui
img = pyautogui.screenshot('test.png')
Environment:
Ubuntu 16.04 (LTS)
conda 4.5.11
Python 3.7 (Miniconda)
requirements.txt:
certifi==2019.3.9
Pillow==5.4.1
PyAutoGUI==0.9.42
PyGetWindow==0.0.4
PyMsgBox==1.0.6
PyRect==0.1.4
PyScreeze==0.1.20
PyTweening==1.0.3
Solution:
I installed python-xlib package in the conda environment using:
pip install python-xlib
Now test_screenshot.py is running without any error.
Updated requirements.txt:
certifi==2019.3.9
Pillow==5.4.1
PyAutoGUI==0.9.42
PyGetWindow==0.0.4
PyMsgBox==1.0.6
PyRect==0.1.4
PyScreeze==0.1.20
python-xlib==0.25
PyTweening==1.0.3
six==1.12.0