flask: command not found - flask 0.12
Fixed by running python3 -m flask.
I have just installed a fresh copy of Ubuntu 16.04 LTS, and installed flask using pip3 install flask. When I run pip3 list Flask 0.12 appears in the list. 
However, when I attempt to run flask, I get the error flask: command not found.
I have also installed using pip and not pip3 but to no avail. Any suggestions?