Easycalc - Prefix and Infix Calculator

Simple Infix and Prefix calculator and Flask-based web api.

Setup

Clone the repo and install python requirments.

Python version >= 3.0.x should be used.

$ git clone https://github.com/robert-hardwick/easycalc.git
$ cd <REPO>/easycalc
$ python -m pip install -r requirements.txt

Standalone CLI

To run command line

$ cd <REPO>/easycalc
$ python main.py cli [prefix|infix] [EXPRESSION]

Example

$ python main.py cli prefix "+ 1 1"
> 2.0
$ python main.py cli infix "3 - 2"
> 1.0

Web API

API Definition provided at easycalc/docs/openapi.yaml

Run API server directly

$ cd <REPO>/easycalc
$ python main.py api --port <PORT> (default = 8888)

Run containerized web service

$ cd <REPO>
$ sh ./start_service.sh

and use docker command to stop/restart the service

$ docker container stop easycalc
$ docker container restart easycalc

Use curl to send some requests

There are 2 API endpoints at /prefix and /infix for each calculator and both endpoints accept a single parameter ?expr which must be encoded in HTML ( e.g. + : %2B , * : %2A and " " : %20)

+ 1 1 :

$ curl http://127.0.0.1:8888/prefix?expr=%2B%201%201
response =
{"return_code":1,"data":2.0,"message":null,"success":true}

3 * 2 :

$ curl http://127.0.0.1:8888/infix?expr=3%20%2A%202
response =
{"return_code":1,"data":6.0,"message":null,"success":true}

Some invalid requests

Unescaped html:

$ curl http://127.0.0.1:8888/infix?expr=3*2
response =
{"return_code":32,"data":null,"message":"Invalid Operator","success":false}

Invalid url:

$ curl curl http://127.0.0.1:8888/somethingelse
response = 404 http response

Run Tests

Install pytest

$ python -m pip install pytest

Run tests

$ cd <REPO>/easycalc
$ python -m pytest tests