Hello world!

This tutorial is a walkthrough on creating a simple Python application for 4Insight EngineRoom. It will show how to structure, package, and upload your application.

Project structure

We will set up a simple Python application named example_app. The application will import two packages, numpy and pandas, and print Hello, World!.

In general, EngineRoom only requires 2 files: run.py and requirements.txt. However, it may be helpful to structure your project locally as:

example_app/
├── README.md
└── src/
    ├── run.py
    └── requirements.txt

The above folder structure is not a requirement, but may be considered as a best practice. The application content in placed under src while other supporting files are placed in root.

run.py is the Python file that is executed by EngineRoom. Open this file and enter the following content:

import numpy
import pandas


print("Hello, World!")

Note that we have not used any of the utilities available in fourinsight.engineroom.utils. This is intentional as the purpose of this tutorial is to show how to set up a bare-minimum application that will run in EngineRoom. A more extensive example with all the bells and whistles is introduced together with the concepts and utilities.

The requirements.txt specifies which Python packages are required to run the application, i.e., so-called dependencies. Open this file and enter the following content:

numpy
pandas

The README.md file may contain a description of the application and information on how to use it. This file is not required by EngineRoom, but it is considered good practice to include it in the project folder. Open the file and enter the following content:

# Example Application

This is a simple example application.

Packaging

For this simple application, run.py and requirements.txt are all we need! Make a zip-file of the content inside the src folder.

example_app.zip/
├── run.py
└── requirements.txt

Upload

Go to https://4insight.io/#/engineroom, and upload the zip-file to your EngineRoom application. Done!