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Environment variables provide a great way to configure your Python application, eliminating the need to edit your source code when the configuration changes. Common configuration items that are often passed to application through environment variables are third-party API keys, network ports, database servers, and any custom options that your application may need to work properly.
In this article I’m going to share some of the techniques and tools available in Python to work with environment variables.
How to access environment variables from Python
Using the os.environ dictionary
In Python, the os.environ dictionary contains all the environment variables. The simplest way to retrieve a variable from inside your application is to use the standard dictionary syntax. For example, this is how you can access an environment variable named USER:
>>> import os
>>> user = os.environ['USER']
>>> user
'miguel'
Using this method, if you try to import an environment variable …
With the release of the Raspberry Pi Pico, the Raspberry Pi Foundation has expanded its product offering beyond their highly successful line of mini-computers and went even smaller by entering the microcontroller market.
Unlike the Raspberry Pi, which functions as a general purpose computer and runs the popular Linux operating system, the Pico is a much more primitive device that lacks a central operating system and can only be programmed to perform specific tasks or control connected peripherals, usually as part of an embedded system or Internet of Things device.
While most microcontrollers can only be programmed in C or C++, the Pico also offers support for MicroPython, a slimmed down version of Python that is designed specifically for small devices. This makes it a great choice for beginners who want to design their own devices but don’t have the patience or interest to learn low-level programming.
In …
Twilio Programmable Video is a robust service based on the WebRTC open standard, which enables real-time communications for web browsers and mobile devices. One of the lesser known features of WebRTC is the ability to stream data in addition to video and audio. The data track is often used to send information that annotates or complements the media streams, but it is also possible to build applications that do not use video and audio and just use the WebRTC data tracks to communicate.
In this tutorial you are going to learn how to use the Twilio Data Track API while building a small browser-to-browser messaging application. The application is going to have a small Flask back end dedicated to the generation of Access Tokens, and a vanilla JavaScript front end that will be able to send real-time notifications to other running instances of the application.
Requirements
To build this …
Twilio APIs make it easy to add communication features to your application, but to consume these APIs you have to keep track of your spending and ensure your account balance stays above zero.
Your balance is available in the main page when you log in to your Twilio Console, but having to actively monitor your account is tedious and inconvenient. In this tutorial you are going to learn how to retrieve your account balance using Python, which will allow you to build automated account balance monitoring within your application!
Prerequisites
To follow this tutorial you will need:
- Python 3.6 or newer. If your operating system does not provide a Python interpreter, you can go to python.org to download an installer.
- A free or paid Twilio account. If you are new to Twilio get your free account now! This link will give you $10 when you upgrade.
Creating a Python …
Several Twilio services can be accessed from a web application running on the browser, but given that this is an inherently insecure platform, the authentication flow is different than for server-based applications.
An application running on the browser needs to obtain an Access Token from your server, and then use this token to authenticate. This is more secure because it prevents you from having to expose your Twilio account credentials in the browser, and also because access tokens have a short lifespan. In this tutorial you are going to learn how this authentication flow works and how to generate access tokens for Twilio services using Python and the Flask framework.
Tutorial requirements
To follow this tutorial you will need:
- Python 3.6 or newer. If your operating system does not provide a Python interpreter, you can go to python.org to download an installer.
- A free or paid Twilio account. If you …
When considering a server push solution for your web application, you will likely evaluate WebSocket, HTTP long-polling, Server-Sent Events and maybe even Socket.IO. In this tutorial I want to introduce you to yet another option that you may not know: Twilio Sync. Sync is a cloud synchronization service that works across browsers and mobile devices and that it is incredibly easy to integrate with your application.
To learn how Twilio Sync works, we are going to add server push capability to a small web application that has a React front end and a Python and Flask back end. We’ll get the job done in just five easy steps!
Note that “server push” in this context refers to technologies that allow web servers to initiate an exchange with clients and “push” events, notifications or data to them. Do not confuse this with “HTTP/2 Server Push”, which is …
If you implemented a video calling application using the Twilio Programmable Video API, you may find that during a call you want to share textual information with the other participants. This could be a link to a document, or even a reaction emoji. In this article you are going to learn how to take your video application to the next level by adding a chat room with the Conversations API.
Tutorial requirements
This is the third article in my series of Programmable Video tutorials, so we are going to take advantage of the video chat application built in the previous two installments and add the chat room feature to it. This application uses a vanilla JavaScript front end and a Python back end. To run this application on your computer you need the following requirements:
- Python 3.6 or newer. If your operating system does not provide a Python …
The Twilio Conversations API is a great way to build a unified messaging solution that works across SMS, MMS, WhatsApp, web and mobile chat. In this tutorial you will learn the basics of the Conversations API by creating a web chat application with support for multiple chat rooms.
The main features of the application we will build are:
- A Flask backend that logs users in.
- A command-line interface to manage your chat rooms.
- A Rect front end that allows your users to chat on the different chat rooms.
Requirements
To follow this tutorial you need the following components:
- Python 3.6 or newer. If your operating system does not provide a Python interpreter, you can go to python.org to download an installer.
- Node.js 14 or newer. Review the installation instructions for your operating system.
- The Yarn package manager for Node.js. Review the installation instructions for your operating system.
- A Twilio account. …
If you are using an asynchronous web server with your Python application, you are bound by the first rule of async development, which is to never call functions that block. So what do you do when you need to use packages such as the Twilio Python Helper Library, which has no asynchronous version?
In this article I’m going to show you some of the options that you have to safely integrate Twilio and similar clients with your async application.
What is the problem?
Before I go into the solutions, I thought it would be good to give a quick review of the issues with blocking in asynchronous applications.
At the core of every async application there is the loop, an efficient task manager and scheduler that ensures that the CPU is shared as fairly as possible among all the running tasks. The type of multitasking used by async …
Um chatbot é um aplicativo de software capaz de conduzir uma conversa com um usuário humano por meio de linguagem escrita ou falada. O nível de "inteligência" entre os chatbots varia muito. Enquanto alguns chatbots têm um entendimento bastante básico da linguagem, outros empregam algoritmos sofisticados de inteligência artificial (IA) e aprendizado de máquina (ML) para alcançar um nível de conversação quase humano.
Nesse tutorial eu vou mostrar a você como é fácil construir um chatbot para Whatsapp usando a API da Twilio para WhatsApp e Flask framework para Python. Abaixo você pode ver um exemplo de interação com o chatbot:
Requisitos do Tutorial
Para seguir esse tutorial você precisa dos seguintes componentes:
- Python 3.6 ou mais recente. Se seu sistema operacional não tem um interpretador Python, você pode ir em python.org para baixar o instalador.
- Flask. Nós vamos criar uma aplicação web que responde mensagens vindas do WhatsApp. …