myflaskr.py

#all the imports 
import sqlite3
from flask import Flask, request,session, g, redirect, url_for, abort, render_template, flash
from contextlib import closing

#configuration
DATABASE= 'tmp/flaskr.db'
DEBUG= True
SECRET_KEY= 'development key' ##more difficult
USERNAME= 'admin'
PASSWORD= 'admin'

#application
app= Flask(__name__)
app.config.from_object(__name__)

def connect_db():
    return sqlite3.connect(app.config['DATABASE'])
    
def init_db():
    with closing(connect_db()) as db:
        with app.open_resource('schema.sql') as f:
            db.cursor().executescript(f.read())
            db.commit()
            
@app.before_request()
def before_request():
    g.db= connect_db()
    
@app.after_request()
def after_request():
    g.db.close()
    return response 
    
@app.route('/')
def show_entries():
    cur = g.db.execute('select.title, text from entries order by desc')
    entries= [dict(title=row[0], text=row[1]) for row in cur.fetchall()]
    return render_template('show_entries.html', entries=entries)
    
@app.route('/add', methods=['POST'])
def add_entry():
    if not session.get('logged in'):
        abort(401)
    g.db.execute('insert into entries (title,text) values(?, ?)',
    [request.form['title'],
    request.form['text']])
    g.db.commit()
    flash('New entry was successfully posted')
    return redirect(url_for('show_entries'))
    
@app.route('/login', methods=['GET', 'POST'])
def login():
    error= None
    if request.method== 'POST':
        if request.form['username']!=app.config['USERNAME']:
            error='Invalid username'
            
        elif request.form['password']!=app.config['PASSWORD']:
            error='Invalid password'
            
        else:
            session['logged_in']=True
            flash('You were logged in')
            return redirect(url_for('show_entries'))
        return render_template('login.html', error=error)
        
@app.route('/logout')
def logout():
    session.pop('logged_in', None)
    flash('You were logged out')
    return redirect(url_for('show_entries')
    
if __name__ == '__main__':
    app.run()