Developing dynamic and interactive web applications has become crucial in the current digital era, and Flask, a flexible and lightweight Python framework, is a great place to start for people who are new to web programming. This article will give you a strong foundation to start your Flask Python journey, whether you’re an experienced programmer exploring new technologies or a coding enthusiast taking your first steps.
We’ll delve into the fundamental concepts, guide you through setting up your development environment, and empower you to build your first web application with Flask. Get ready to unlock the potential of web development as we demystify Flask and pave the way for your exciting learning experience. So in this article, you will be clear your doubts on topic flask in python , what is flask in python , what is flask used for and flask framework and its components.
This article was published as a part of the Data Science Blogathon.
Python’s Flask micro web framework can be used to build web-based apps for interacting and displaying data-driven content. Although Flask is more frequently associated with web development, it can also be used in data science to create straightforward web interfaces, APIs (Application Programming Interfaces), and visualisation tools that enable data scientists and analysts to present their data and analyses in a user-friendly and interactive way.
Python’s Flask micro web framework is well-liked and frequently used to create online apps. It offers a straightforward and adaptable method for developing Python-based web applications and APIs (Application Programming Interfaces). Flask is renowned for its straightforward design, which gives developers the freedom to select the elements they desire and customise their apps to meet their needs.
Here are some common uses of Flask:
The framework is the basis upon which software programs are built. It serves as a foundation for software developers, allowing them to create a variety of applications for certain platforms. A set of functions and predefined classes used to connect with the system software and handle inputs and outputs. The life of a developer while giving them the ability to use certain extensions and makes the online applications scalable and maintainable.
Flask is a popular Python web framework that allows you to create web applications quickly and easily. Some of the key features of Flask are:
Flask is used for developing web applications using python, implemented on Werkzeug and Jinja2. Advantages of using Flask framework are:
Install the latest version of Python or at least use a version >= Python 3.7
Virtual environments are separate collections of Python libraries, one for each project. Installed packages for one project do not affect other projects or the operating system’s packages. Python has the venv package, which allows you to build virtual environments.
> mkdir myproject
> cd myproject
> py -3 -m venv venv
$ mkdir myproject
$ cd myproject
$ python3 -m venv venv
Before you begin working on your project, turn on the environment:
> venvScriptsactivate
$ . venv/bin/activate
The name of the current active environment will be shown in your shell prompt.
Run the following command in the active environment to install Flask:
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<pre>$ pip install Flask</pre>
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Let’s make our first flask app now. Flask application may look like this:
Python Code:
from flask import Flask
app = Flask(__name__)
@app.route("/")
def home():
res = "Hello, World! This is our first Flask app."
return res
if __name__ == "__main__":
app.run(host='0.0.0.0', port=80)
If everything works fine this will start a built-in server, which is used for testing but probably not suitable for production usage, your console will show the following output:
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This means that our app is running on http://127.0.0.1:5000/. Here 127.0.0.1 is the default IP address.
Now let’s understand the code:
The flask run command is capable of doing more than simply starting the development server. When we enable debug mode, the server will immediately reload if the code changes, and an interactive debugger will appear in the browser if an error occurs during a request.
Creating fixed URLs is so damn simple. Users are more likely to enjoy and return to a website if it has a meaningful URL that they can remember and use to get directly to the page. To assist users, modern online apps employ meaningful URLs. To tie a function to a URL, use the route() decorator.
@app.route('/')
def index():
return 'This is Home Page'
@app.route('/hello')
def hello():
return 'This is Hello, World Page'
Now let’s understand the code:
In this way, we can render as many distinct web page URLs we want.
As we can understand from the name that static routes are fixed routes i.e. for each route functionalities we have to explicitly define the same function for each URL route.
@app.route('/Elon')
def greet():
return 'Welcome Elon. What would you like to order.'
@app.route('/John')
def hello():
return 'Welcome John. What would you like to order.'
This code will greet different users with the same message.
Although implementing the same function for multiple routes isn’t a big problem until you get to a certain number of routes. It quickly becomes a frantic process when we are dealing with hundreds of routes.
Instead of defining the same function for each route, we can add variable sections to a URL by annotating sections with . The variable name is then sent to the defined function as the parameter.
@app.route('/')
def greet(name):
return f'welcome {name}. What would you like to order.'
in the route captures a value from the URL and passes it to the function. So even if million of users route this web page we can handle all the routes by defining merely one function.
We can also use a converter to define the type of the parameter, such as.
Defining datatype along with variable name enforces the user to follow the convention while passing the route name to the server.
int | only accepts positive integers |
float | only accepts positive floating-point values |
string | accepts text (by default) without a slash |
path | like string but also accepts slashes |
uuid | accepts UUID strings |
HTML injection is a way of modifying a web page that an application presents to its users by using non-validated input. If a program does not validate the user data, an attacker can send a malicious text in HTML format which can modify the content of the site, seen by other users. A query can result in the insertion of attacker-controlled HTML elements into a web page, changing the way application content is on the web.
To defend against injection attacks, it’s essential to enclose all user-provided values when rendering output in HTML (the default response type in Flask).
Use the escape() function manually. Most examples remove it for brevity, but you should always be mindful of how you’re accessing untrusted data.
from flask import escape
@app.route("/")
def hello(name):
return f"Hello, {escape(name)}!"
When we are searching for any web pages, to access their server and client employs several HTTP methods to communicate. As you work with Flask, you should become familiar with the HTTP methods.
The Hypertext Transfer Protocol (HTTP) is a protocol that allows clients and servers to share information. HTTP is a request-response protocol to communicate between a client and a server. A client (browser) sends an HTTP request to the server, and the server answers.
Currently, we will look at GET and POST, these are the most common methods.
GET Method
Use GET to fetch information from a certain website.
POST Method
Use POST to send data to a server to update or create a resource.
from flask import request
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'POST':
return do_the_login()
else:
return show_the_login_form()
A route, by default, only responds to GET queries. The route() decorator’s methods parameter may handle HTTP methods.
In the realm of Python web development, Flask shines as a light of simplicity and versatility. Whether it’s a prototype, a microservice, or a small-to-medium-sized web platform, its basic approach empowers developers to create applications that closely match their requirements. Flask promotes creativity and innovation by providing a balance between flexibility and structure, allowing developers to concentrate on their concepts and solutions rather than the specifics of the framework itself. Flask is quite versatile and use it for data research, API development, and more, making it a crucial tool for anyone looking to use Python in the dynamic world of web development.
Hope you clear the article and now you know all about the flask framework and what is flask used for, what is flask in python how it can be used so you will clear all about these topic.
With its straightforward and adaptable Flask framework, use Python to construct web apps and APIs that are interactive and data-driven.
Flask is a simple tool for building websites using Python. It helps you create web pages and handle user requests easily. Think of it as a basic toolkit for making websites.
The choice between Flask and Django depends on project complexity; Flask suits smaller, custom applications, while Django offers more features for larger, structured projects.
Flask is backend. It handles server-side logic.
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