Flask and Eclipse integration: Python web application development tips (Part 3)

Flask and Eclipse Integration: Python web application development tips (Part 3)

In the first two articles, we introduced how to integrate Flask with Eclipse and how to create Flask applications. In this article, we will continue to explore how to develop and debug Flask applications, as well as how to manage databases.

1. Develop and debug Flask applications

1. Create and run Flask applications

In Eclipse’s Project Explorer, find your Flask application Program project, then right-click the application file app.py and select Run As > Python Run.

In the Console view of Eclipse, you should see information similar to the following:

• Serving Flask app "app" (lazy loading)
• Environment: development
• Debug mode: on
• Running on http://127.0.0.1:5000/ (Press CTRL C to quit)

After successful operation, you You can view your Flask application by entering http://127.0.0.1:5000/ in a web browser.

2. Debug Flask Application

In the Debug view of Eclipse, set a breakpoint and re-execute the above steps to run the Flask application.

When the application executes to the breakpoint you set, the application will automatically pause. At this point, you can step through program execution, view the values ​​of variables and functions, and modify them to test your code.

The application stops automatically when you finish debugging and exit debug mode.

2. Management database

1. Database configuration

Flask applications can access and manage the database through SQLAlchemy ORM.

To use SQLAlchemy, add the following code to the application file app.py:

from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config ['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///db.sqlite'
db = SQLAlchemy(app)

2. Create database model

In the application file app.py, you need to define your database model.

The following is a simple example:

class User(db.Model):

id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(128))

def __init__(self, name):
    self.name = name

def __repr__(self):
    return '<User %r>' % self.name

This model defines a database table named "User", which Includes two columns: id and name. id is the primary key of the table. Each time a new user is created, the ID is automatically incremented. The name column is the user's name.

3. Create database table

In the console, type the following command to create the database table:

from app import db
db.create_all( )

This command will create all defined models in the database.

4. Add data to the database

In the console, type the following command to add users to the database:

from app import db
from app import User

user = User('John')
db.session.add(user)
db.session.commit()

This command will create a file named user "John" and add him to the database.

5. Query the database

In the console, type the following command to query the user from the database:

from app import db
from app import User

users = User.query.all()
for user in users:

print(user.name)

This command will query all users in the database and print their names to the console .

Summary

In this article, we introduced how to develop and debug Flask applications, and how to manage databases. Flask is an excellent Python web framework. You can quickly build and manage Flask applications using the Eclipse IDE. If you haven’t tried it yet, be sure to give it a try!

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