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Tag: web

PyQt5 webkit browser

QWebview inside a browser PyQt5 Webkit (QWebview) inside a browser

PyQt5 comes with a webkit webbrowser. Webkit is an open source web browser rendering engine that is used by Apple Safari and others. It was used in the older versions of Google Chrome, they have switched to the Blink rendering engine.

Related course:
Create GUI Apps with PyQt5

QWebView
The widget is called QWebView and webpages (HTML content) can be shown through this widget, local or live from the internet.

Download Example Code

Methods
The QWebView class comes with a lot of methods including:


  • back (self)

  • forward (self)

  • load (self, QUrl url)

  • reload (self)


More documentation on this class can be found on ics.uci.edu


#!/usr/bin/python

import PyQt5
from PyQt5.QtCore import QUrl
from PyQt5.QtWidgets import QApplication, QWidget
from PyQt5.QtWebKitWidgets import QWebView , QWebPage
from PyQt5.QtWebKit import QWebSettings
from PyQt5.QtNetwork import *
import sys
from optparse import OptionParser

class MyBrowser(QWebPage):
''' Settings for the browser.'''

def userAgentForUrl(self, url):
''' Returns a User Agent that will be seen by the website. '''
return "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36"

class Browser(QWebView):
def __init__(self):
# QWebView
self.view = QWebView.__init__(self)
#self.view.setPage(MyBrowser())
self.setWindowTitle('Loading...')
self.titleChanged.connect(self.adjustTitle)
#super(Browser).connect(self.ui.webView,QtCore.SIGNAL("titleChanged (const QString&)"), self.adjustTitle)

def load(self,url):
self.setUrl(QUrl(url))

def adjustTitle(self):
self.setWindowTitle(self.title())

def disableJS(self):
settings = QWebSettings.globalSettings()
settings.setAttribute(QWebSettings.JavascriptEnabled, False)

app = QApplication(sys.argv)
view = Browser()
view.showMaximized()
view.load("https://pythonspot.com")
app.exec_()

Related course:
Create GUI Apps with PyQt5

Python Web Development Frameworks

Introduction


pythonQuote

Web apps are often created using a framework. Frameworks make it easier to develop web apps that are scalable, reliable and maintainable. It avoids recreating the same code over and over again.
Common features are:

  • URL Routing
  • Output templates
  • Database management
  • Session management
  • Security against common attacks

A framework may offer some or all of these features.

For example, the Flask web application framework does not have database support and you would need a separate module to use a database. The Django web application framework supports databases by default.

Related course: Create Web Apps with Python Flask

Python Hosting

To run your app on the web, you will need hosting. Unless you want to do hosting yourself, you need a party to host.
Hosting servers:

Why use a web framework?

As you are doing web development, you want to avoid spending time on programming things that have already been solved. On the other hand, if you are an experienced web developer a web framework may not offer everything you need.

What Python web frameworks exist?


Django and Flask are the most popular web frameworks. However, you may want to evaluate the frameworks. An overview:


The most popular python web application framework is Django, followed by Flask.

python web development # of projects on Github mentioning a framework.

Django

Django is the most used Python web framework. It takes care of many things so you can focus on the web app development. Sites built withDjango have dealt with high traffic spikes such as 50 thousands hits per second.

Database access is achieved through an Object-relational mapper: You define your data models in Python and Django deals with the actual database management systems (SQL). However, if you need to you can write your own SQL Queries with Django. URL routing is supported by Django. It encourages beautiful URL design such as ending without .php or .asp.

Features:

  • Object-relational mapper
  • URLs routing and views
  • Template engine
  • Forms
  • Authentication
  • Admin
  • Internationalization
  • Security

If you want to know more about Django, read here.

Did you know the websites of NASA, Bitbucket and Pinterest were made with Django?

Related course: Django Web Developer Course

Flask

flask-logo
Flask is a Python micro framework which is modular by design. The framework is intended to build web apps. Flask does not have a specific database system or ORM system. If you want to use a database, you’ll have to use extensions. Flask is often combined with SQLAlchemy for database use.

Flask is very easy to get running, a minimal app would be:

from flask import Flask
app = Flask(__name__)

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

if __name__ == '__main__':
app.run()

The framework supports URL routing, template (using Jinja2), session management and has some out of the box security.
Features:

  • URL Routing and views
  • Template engine
  • Session management
  • Logging

If you want to know more about Flask, read here.

Related course: Create Web Apps with Python Flask

Flask with static html files

You can use the Flask framework and use static files together.

Flask will give you URL routing, many features and all the Python benefits.

You may want an application that is partly dynamic and partly static. Or you may simply want to browse with URL routing. In this article we will teach you how to load static HTML files with Flask.

Related course
Python Flask: Make Web Apps with Python

from flask import Flask, render_template

app = Flask(__name__)

@app.route('/<string:page_name>/')
def render_static(page_name):
return render_template('%s.html' % page_name)

if __name__ == '__main__':
app.run()

This application initializes a Flask app with the method:


app.run()

The app creates an URL route for any possible page and links that to static html files with:


@app.route('/<string:page_name>/')
def render_static(page_name):
return render_template('%s.html' % page_name)

</string:page_name>

Create a directory /templates/ and add the file hello.html:



<title>Hello World Template</title>

Hello World


Start the server with:

$ python app.py
* Running on http://127.0.0.1:5000/

Then any .html file is accesible using URL routing.

For example the static file hello.html can be accessed using http://127.0.0.1:5000/hello. You can store any css file in the /static/ directory.

Download Flask Examples

JSON encoding and decoding with Python

Creating a web-browser with Python and PyQT