app.py

from flask import Flask, render_template,request,redirect, url_for
from  flask_sqlalchemy import SQLAlchemy


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

class Todo(db.Model):
    id = db.Column(db.Integer,primary_key=True)
    task = db.Column(db.String(150))
    complete= db.Column(db.Boolean)


@app.route('/')
def index():
    data=Todo.query.all()
    return render_template("base.html", context=data)

@app.route("/add", methods=["POST","GET"])
def add():
    task=request.form.get("task")
    # title=request.args.get("title")   # to get args from get
    new_todo=Todo(task=task,complete=False)
    db.session.add(new_todo)
    db.session.commit()
    return redirect(url_for("index"))


@app.route("/edit/<int:todo_id>")
def edit(todo_id):
    todo=Todo.query.filter_by(id=todo_id).first()
    todo.complete=not todo.complete
    db.session.commit()
    return redirect(url_for("index"))

@app.route("/delete/<int:todo_id>")
def delete(todo_id):
    todo=Todo.query.filter_by(id=todo_id).first()
    db.session.delete(todo)
    db.session.commit()
    return redirect(url_for("index"))



if __name__=="__main__":
    with app.app_context():
        db.create_all()
    app.run(debug=True)