python3 is not recognized as an internal or external command, operable program or batch file showing for creating django runserver
For anyone for whom the answer above does not work. You can try this one(For windows only). Find the folder where python 3 installed in your computer. You will see that there is a python.exe. Just copy-paste that file inside that folder once and rename that file as python3.exe. Now all Python commands which starts with python3 .... will work for you in Windows command line. It works because windows installation of Python does not expect commands starting with in "python3 ...." format. But with just doing this you can use all commands starting with "python3" hassle-free. Enjoy! Remember that, this solution  considers that you added python 3 path to the system variables of windows system beforehand.
(venv) C:\Users\Inter-Wave\PycharmProjects\PyShop>python3 manage.py runserver
'python3' is not recognized as an internal or external command,
operable program or batch file.