krisztinasinkovics/Prefix_Infix_Calculator

Simple calculator with a Flask app handling prefix and infix notations

This is a repository hosting a simple calculator that can handle prefix and infix expressions. You can interact with it both as a web-based application and as a standalone script.

Requirements:

python version: 3.7
testing:
pytest==6.1.2

app:
flask==1.1.2
wtforms==2.3.3

Assumptions:

• All the tokens are space-separated, including the parenethesis tokens for infix notation
• Expressions are assumed to be given correctly
• The system should support the operators {+, -, *, /} which all take exactly two args.
• The input literals are positive integers
• Calculations can be done in the floating-point or integer domain
• In case of prefix notation operator precedence is handled by the specifics of the notation
• In case of infix notation operator precedence is handled by the parenthesis

How to run:

Option 1:

To start the web-based application (on your localhost) run the following:
$ python main.py --mode web-based
open http://127.0.0.1:7089/ in your browser
You should be able to see this:

Option 2:

To use the calculator in a standalone script mode run the following:
$ python main.py --mode script --expression_type prefix for evaluating prefix expression
$ python main.py --mode script --expression_type infix for evaluating infix expression