One more possible solution at Troubleshooting page

Symptom	Things to try
python gives me a “command not found” error or opens the Store app when I type it in my terminal.	...
py gives me a “command not found” error or opens the Store app when I type it in my terminal.	...
...	...
pip gives me a “command not found” error or opens the Store app when I type it in my terminal.	...

— at Python Setup and Usage > 4. Using Python on Windows > Troubleshooting

Here's one more possible reason for the symptoms above: the terminal just doesn't get PATH Variable updated (if PATH is modified when the terminal is still running).
And the respective solution is simple: Check PATH and reopen the terminal, then try again.

Linked PRs

• gh-143964
• gh-143981

Ouvrez la page Python Setup and Usage > Using Python on Windows > Troubleshooting liée dans l’issue et examinez le tableau des symptômes existant. Comparez les indications proposées concernant PATH et le redémarrage du terminal avec les PR liées gh-143964 et gh-143981 ; la documentation est terminée lorsque les indications convenues apparaissent sur la page Troubleshooting.