This is minimal flask application of Calculator which performs following Operations:

[1] Addition (OPERATION: +)

[2] Subtraction (OPERATION: -)

[3] Multiplication (OPERATION: *)

[4] Division (OPERATION: /)

Inside template/

[1] form.html

This carry data i.e. variables on which operations to be performed and operation code which has to be performed on variables.

[2] result.html

This displays the result of the user query.

Go to terminal and inside the project directory, and type the following command:

$ python calc.py

The server is started and now goto your browser and open URL localhost:5000.