Upgrade python to 3.10 in windows; Do I have to reinstall all site-packages manually?

I upgraded to python 3.10.2 in windows 10 64 bit. To properly install the packages, install the appropriate version of the Microsoft Visual C++ compiler if necessary. Details can be read https://wiki.python.org/moin/WindowsCompilers . With the upgrade to python 3.10.2 from 3.9, it turned out that I had to do it, due to errors that are appearing during the installation of the packages. Before the installing python 3.10.2, type and execute the following command in the windows command prompt:

pip freeze > reqs.txt

This command writes to the reqs.txt file the names of all installed packages in the version suitable for pip. If you run the command prompt with administrator privileges, the reqs.txt file will be saved in the directory C:\WINDOWS\system32.

Then, after the installing of python 3.10.2 and the adding it to the paths in PATH, with the help of the command prompt you need to issue the command:

pip install -r reqs.txt

This will start the installing of the packages in the same versions as for python 3.9. If problems occur, e.g. an installation error appears during the installation of lxml, then you can remove from the regs.txt file the entry with the name of the package whose installation is causing the problem and then install it manually. To edit the reqs.txt file you need the administrator privileges. The easiest way is to run the command prompt in the administrator mode, type reqs.txt and click Enter to edit it.

I decided later to update the missing packages to the latest version, because I suspected that with python 3.10.2 older versions were not compatible. This means that when upgrading to python 3.10.2 it is worth asking yourself whether it is better to upgrade for all packages. To do this, you can generate the list of the outdated packages using the command:

pip list –-outdated

After the printing of the list in the command prompt, you can upgrade the outdated packages using the command:

pip install --upgrade <package-name>

This can be automated by the editing of the reqs.txt file and the changing of the mark == to > which will speed up the upgrade. The mark > should only be changed for the outdated packages or you will get an error: "Could not find a version that satisfies the requirement ... ".

Supplement to virtual environments:

When you enter a virtual environment directory (in the windows command prompt):, such as D:\python_projects\data_visualization\env\Scripts, type activate to activate it. Then create the reqs.txt file analogous to the description above. Then, copy the file to a temporary directory. After this delete the virtual environment, e.g. using the windows explorator by the deleting of the contents of the env directory. Then, using the version of python in windows of our choice, create a virtual environment using the env directory (see: https://docs.python.org/3/library/venv.html). Copy the regs.txt file to the newly created D:\python_projects\data_visualization\env\Scripts directory. Install site-packages with the support of the regs.txt file as described above.

No you need not reinstall python packages.

conda create --name project-env python=3.x

You can also look at an alternative method to install python versions Install python version