Error: No module named flask in python

Error: No Module named flask, for python application

(venv) C:\Python\sandbox>py -m flask run

C:\Python\sandbox\venv\Scripts\python.exe: No module named flask

When you try to run the python application using flask you may get the above error: 

root cause: There is no flask installation found in the directory you are currently trying to access the application.

Solution:

When you over come the above error first install flask using below command:

py -m pip install Flask

Then try: py -m flask run 

Now your system will recognize your command and run the flask application.