What is Flask Python? A short Flask framework tutorial

Flask Python is a slim web framework, suitable for beginners and pro­fes­sion­als alike. Flask is limited to including only the es­sen­tials, but users can implement external libraries to expand its func­tion­al­ity.

Python is a popular internet pro­gram­ming language favoring the use of simple and short code. The neat pro­gram­ming style minimizes errors and users can quickly get their heads around a Python tutorial. Developed by Guido van Rossum in 1991, it’s now used and main­tained by a large community under the su­per­vi­sion of the non-profit Python Software Found­a­tion. Python is open source and platform in­de­pend­ent. Python is a dynamic language. It supports object-oriented and func­tion­al pro­gram­ming such as logging and can be executed as CGI script.

Various web frame­works are available to use Python to create dynamic websites and develop web ap­plic­a­tions. These provide the necessary code to ease the de­vel­op­ment process and simplify repeat tasks. Issues or common Python errors can be avoided and web services are up and running faster and in a more secure manner. Fre­quently required functions can be adopted directly and don’t require in­de­pend­ent pro­gram­ming. One of the best-known web frame­works for Python is Django CMS, which is a full-stack solution providing a large toolbox of different functions. However, due to its size it’s also com­par­at­ively rigid. One of the best-known counter frame­works is Flask.

While full-stack frame­works such as Django provide de­velopers with their own libraries, Flask Python takes a different approach. The web framework launched by Austrian developer Armin Ronacher in 2010, takes a more min­im­al­ist approach. Flask only includes the template engine Jinja and a library called “tool”. But it offers the pos­sib­il­ity to integrate third-party functions. The Flask framework is under a BSD license. It’s free and open source. As a counter-design to Django and other frame­works, Flask Python was quick to inspire a large fan community.

Before setting up Flask for Python, make sure you meet the re­quire­ments. You’ll need Python 2 or 3 installed. You will also need a text editor or IDE and access to the internet. Having some basic knowledge of Python is useful. An un­der­stand­ing of pro­gram­ming, data types, and for-loops is also ad­vant­age­ous. Flask is a good starting point to learn how to build web ap­plic­a­tions. You set up the framework as follows:

1. Create a virtual en­vir­on­ment to separate the new project from the rest of your Python libraries or projects and avoid problems with your system. The code looks like this:

2. Install Flask. The best way to do this is to use the package man­age­ment program pip. The ap­pro­pri­ate command is:

3. Check if the in­stall­a­tion has been suc­cess­ful:

4. Now you can test Flask and create a basic ap­plic­a­tion. To do this, open a file in your directory. Here, we call it start.py and use nano to access it:

5. Write the following code into the file:

6. Save and close the file.
7. Use the en­vir­on­ment variable FLASK_APP to point Flask to the location of the cor­res­pond­ing file:

8. Use FLASK_ENV to export the file in developer mode:

9. Now run the ap­plic­a­tion:

The output should look something like this:

There are good reasons for using Flask. However, a few things speak against it. For this reason, it’s worth taking a closer look at the pros and cons of the web framework.

• Scope: You will hardly find a more stream­lined framework than Flask Python. Flask is quick to install and use.
• Flex­ib­il­ity: Flask offers out­stand­ing flex­ib­il­ity. You can solve problems and implement the libraries you need, ap­proach­ing each project in­di­vidu­ally.
• Learning curve: Flask is quick to learn using a Flask tutorial. The framework is de­lib­er­ately simple, but can equally be used for chal­len­ging projects. Flask is a great choice for beginners and pro­fes­sion­als alike.
• Open source: The Flask framework is open source and available for free. Simply give it a try and find out if it’s the right tool for your needs.
• Community: Flask is supported by a huge community providing advice and support to newcomers and more ex­per­i­enced de­velopers. Questions and errors are rapidly answered and solved.

• Scope: Depending on intended use, its min­im­al­ist scope can be dis­ad­vant­age­ous. All tools require in­di­vidu­al in­stall­a­tion. Al­tern­at­ive frame­works offer sig­ni­fic­antly more pre-installed functions.
• De­pend­ency on third-party providers: The use of external libraries is always a possible source of errors, but Flask depends on them.
• Main­ten­ance: While other frame­works are auto­mat­ic­ally main­tained, Flask shifts that re­spons­ib­il­ity to the user. This means more control, but it also creates more work.

Flask isn’t just a great way to get to know how to work with web frame­works but is suitable for more demanding projects. The micro-framework comes in handy for those in need of more flex­ib­il­ity. Whether Flask Python is the right choice depends on your needs and the nature of your project. Check out our com­par­is­on of Flask vs Django in our Digital Guide.