Python , PyQt5 , Qt Creator , DLL load error , missing Qt bindings , pyqt , anaconda

Описание: UPDATE! (2022/08/14)
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Just use PyCharm and install PyQt5 in the venv of a project. Worked fine directly. Could have saved me a week of problem solving with Anaconda. As Anaconda and Spyder basically depend on PyQt, doing changes there is just causing unnecessary problems.
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Just wanted to share my experience/solution for a problem I`ve been searching for nearly a week now. Maybe there`s someone out there who can use this and save a few days of debugging.

as of 10th March 2022

Operating System:

Windows 10 Professional

Python IDE/setup:

anaconda3, v. 2.1.2

What I wanted to do:

Use the designer of QtCreator to create a GUI, convert the .ui file to .py file and make it working in Python, using spyder

nice video with detailed instructions (in German language) for how to do that:

   • Python Tutorial, GUI-App mit Qt: #2 Erstes...  


Problems that occured:

DLL load failed while importing PySide2, or any other Qt related module
some more DLL problems
missing "Qt-bindings" for several apps in Anaconda
installing PyQt5 with the newest version led to: Spyder not starting anymore, loads of QtGui/QtCore/QtWidgets not working properly anymore,
anaconda doesn't start anymore... (+ much other stuff)

What I did in the end and now don't know how it is working (after 5-6 days of research...):

if anaconda doesnt start:

conda prompt:

conda uninstall pyqt
conda uninstall qtpy
conda install pyqt (current v. 5.9.2)
conda install qtpy (current v. 1.11.2)

check installed versions with:

conda search -f [package name]

anaconda works again:

create virt env with Python 3.8.12
pip3 install pyqt5==5.12.3
pip3 install pyside2==5.14.0
pip3 install pyqt5-tools==5.12.3.1.6rc1
conda install spyder (current v. for anaconda 5.1.5)

check installed versions with:

pip3 show [package name]