Code Playground.

Flagon is a free and open-source miniature web structure for Python intended to assist designers with building secure, versatile and viable web applications. Carafe depends on Werkzeug and utilizations Jinja2 as a layout motor. 

In contrast to Django , of course Flask does exclude ORM, structure approval or some other functionalities gave by outsider libraries. Jar is worked in light of augmentations, which are Python bundles that add usefulness to a Flask application. 

There are various techniques to introduce Flask, contingent upon your requirements. It very well may be introduced framework wide or in a Python virtual climate utilizing pip. 

Carafe bundles are likewise remembered for the EPEL archives and can be introduced utilizing the yum bundle supervisor. This is the simplest strategy to introduce Flask on CentOS 7, however not as adaptable as introducing in a virtual climate. Additionally, the adaptation remembered for the vaults consistently falls behind the most recent variant of Flask. 

The fundamental reason for Python virtual conditions is to establish a secluded climate for various Python ventures. This way you can have various diverse Flask conditions on a solitary PC and introduce a particular form of a module on a for each venture premise without stressing that it will influence your other Flask establishments. On the off chance that you introduce Flask into the worldwide climate, at that point you can introduce just a single Flask form on your PC. 

Installing Flask on CentOS 7

In the accompanying areas, we'll give subtleties on the best way to introduce Flask in a Python virtual climate on CentOS 7. 

1. Installing Python 3 and venv

We will introduce Python 3.6 from the Software Collections (SCL) stores. 

CentOS 7 boats with Python 2.7.5 which is a basic piece of the CentOS base framework. SCL will permit you to introduce fresher renditions of python 3.x close by the default python v2.7.5 with the goal that framework instruments, for example, yum will keep on working appropriately. 

Empower SCL by introducing the CentOS SCL discharge document which is remembered for the CentOS additional items archive: 

sudo yum install centos-release-scl

When the archive is empowered introduce Python 3.6 with the accompanying order: 

sudo yum install rh-python36

When Python 3.6 is introduced we are prepared to establish a virtual climate for our Django application. 

2. Creating a Virtual Environment

Start by exploring to the registry where you might want to store your Python 3 virtual conditions. It very well may be your home index or whatever other registry where your client has peruse and compose authorizations. 

To get to Python 3.6 you have to dispatch another shell occasion utilizing the scl device: 

scl enable rh-python36 bash

Make another index for your Flask application and explore into it: 

mkdir my_flask_app
cd my_flask_app

Run the accompanying order to establish another virtual climate: 

python3 -m venv venv

The order above will make an index called venv, which contains a duplicate of the Python parallel, the Pip bundle administrator , the standard Python library and other supporting documents. You can utilize any name you need for the virtual climate. 

Initiate the virtual climate utilizing the enact content: 

source venv/bin/activate

When initiated, the virtual climate's receptacle registry will be added toward the start of the $PATH variable. Likewise your shell's brief will change and it will show the name of the virtual climate you're as of now utilizing. For our situation that is venv. 

3. Installing Flask

Since the virtual climate is enacted, you can utilize the Python bundle administrator pip to introduce Flask: 

pip install Flask

Inside the virtual climate, you can utilize the order pip rather than pip3 and python rather than python3. 

Confirm the establishment with the accompanying order which will pr

python -m Flask --version

int the Flask variant: 

python - m Flask - form 

At the hour of composing this article, the most recent authority Flask rendition is 1.0.2 

Flask 1.0.2
Python 3.6.3 (default, Mar 20 2018, 13:50:41) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]

Your Flask form may contrast from the variant appeared here. 

4. Creating a Minimal Flask Application

In this guide, we will make a straightforward hi world application that will show the content "Hi World!". 

Open your word processor or Python IDE and make the accompanying record: 

~/my_flask_app/hello.py

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello World!'

How about we break down the code line by line. 

In the primary line, we are bringing in the Flask class. 

Next, we making a case of the Flask class. 

At that point we utilize the course() decorator to enroll the hello_world work for the/course. At the point when this course is mentioned, hello_world is called and the message "Hi World!" is gotten back to the customer. 

Spare the record as hello.py and return to your terminal window. 

5. Testing the Development Server

We'll utilize the carafe order to run the application yet before that, we have to disclose to Flask how to stack the application by determining the FLASK_APP climate variable: 

export FLASK_APP=hello.py
flask run

The order above will dispatch the advancement builtin worker. 

The yield will look something like the accompanying: 

 * Serving Flask app "hello.py"
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

On the off chance that you introduced Flask on a virtual machine and you need to get to Flask advancement worker then you can make the worker freely accessible by annexing - host=0.0.0.0 to the cup run order. 

Open http://127.0.0.1:5000 in your internet browser and you will be given the "Welcome World!" message. 

To stop the advancement worker type CTRL-C in your terminal. 

6. Deactivating the Virtual Environment

Whenever you are finished with your work, deactivate the climate, by composing deactivate and you will re-visitation of your typical shell. 

deactivate

Conclusion

You have figured out how to establish a Python virtual climate and introduce Flask on your CentOS 7 machine. To establish extra Flask advancement conditions rehash the means we illustrated in this instructional exercise. 

In the event that you are new to Flask, visit the Flask documentation page and figure out how to build up your first Flask application. 

Don't hesitate to leave a remark beneath.