Installed Flask in a virtualenv yet "command not found"
Flask 0.10 has no flask command, it was added in 0.11. If pi.py has the smarts to run your app, such as if it's using Flask-Script, the command you're looking for is:
$ python pi.pyYou can install Flask-CLI to get the flask command in 0.10 if you can't upgrade to 0.11.
I ran into this issue while running through the tutorial for version 0.12, so for people who find this thread hitting this issue with a later version, I was able to get the server running by using:
$ python -m flask run
You need to upgrade flaskUse the following command on the terminal in your virtual environment
pip install --upgrade Flask