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Tag archive for: Python Flask

Getting the environment variables supplied to your Cloud Foundry application with Python 3 Flask

When I was trying to build a Python 3 Flask application on Cloud Foundry, I wanted to quickly check the environment variables that Cloud Foundry will supply to my application.

As a result of that, I created a Python 3 Flask application that will probe the environment variables that it receives from Cloud Foundry.

This post lists the files that constitute that Python 3 Flask application.

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How to read temperature and humidity from a DHT11 sensor that is connected to a Raspberry Pi 3

I had always wanted to measure the temperature and humidity of the environment where my herbs are grown at.

Since I had a few pieces of Raspberry Pi 3 lying around the house, I decided to use one of them to measure the temperature and humidity of the area of the house where my herbs are.

An additional sensor is required to measure the temperature and humidity of the environment. Therefore, I went to AliExpress and got a DHT11 sensor. By connecting a DHT11 sensor to my Raspberry Pi 3, I can give it the ability to read the temperature and humidity of its environment.

Given these points, I created this post to show how to read temperature and humidity from a DHT11 sensor that is connected to a Raspberry Pi 3.

In order for us to check the temperature and humidity from the DHT11 sensor, we will build a simple Flask application that returns the temperature and humidity values as HTTP responses to HTTP clients.

How to paginate MongoEngine records in your Python 3 Flask application

Flask and MongoEngine help makes development work easier.

One common task in the development of backend applications is the pagination of database records. Without pagination, the application server can run out of memory while generating a response from the database records.

This post discusses a way to paginate MongoEngine records in your Python 3 Flask application using the facilities provided by the Flask-MongoEngine extension.

How to deploy Python 3 Flask application on Raspberry Pi 3 with Raspbian Stretch Lite, Nginx, Supervisor, Virtualenv and Gunicorn

Raspberry Pi 3 Model B boards make good gifts for programmers and if someone had gifted you with one, you may want to use it as a control center for interacting with various IoT sensors and devices at home.

In such a situation, you may want to build a Python 3 Flask application to present the web interface for accessing the control center.

After you had built that Python 3 Flask application, the next step will be to deploy it on your Raspberry Pi 3 for serving HTTP requests.

This post discusses how you can deploy a Python 3 Flask application on Raspberry Pi 3 with Raspbian Stretch Lite, Nginx, Virtualenv and Gunicorn.

How to enable authenticated MongoDB access for Flask-MongoEngine applications

After having a first look at MongoDB more than 5 years back, I told myself that I will use MongoDB to realise the next functionality of Techcoil.

With exposure to Python 3, Flask and MongoEngine in 2017, I had acquired the skills to build a microsite to recommend gift ideas. This microsite uses MongoDB to store the gift recommendation data.

With Flask and MongoEngine, development of this microsite did not take too much leisure time. With MongoDB not enforcing authentication, there were not much hindrance in setting up the development environment for this microsite.

However, this free-for-all mode of accessing MongoDB is not recommended for production environments. Without authentication, it is easier for ill-intentioned people to mess up the backend database.

To ensure that I have a go-to post for implementing authenticated access to MongoDB backed projects in the future, I document the steps needed for Flask-MongoEngine applications to access MongoDB instances with access control turned on.