Having got "hello world" working on your server in Flask (see [here] if you haven't!), you'll want to add further routes for other URLs - and indeed you'll want those routes to contain match markers so you can set up whole families of URLs. Our first example included:

  @app.route("/")
  def hello():
    etc

and we'll now add some further routes (using the route decorator):

  @app.route("/<word>")
  def greet(word):
    return "This is the page called {0:s} under flask".format(word)

  @app.route("/<folder>/<word>")
  def greeting(folder,word):
    return "This is the page called {0:s} in the {1:s} folder".format(word,folder)

Sample outputs:

 


and you can also include rules such as
  @app.route('/post/<int:post_id>')
which will only match an integer. Also float and path are available - for a floating point number, and for a complete path including "/" which isn't allowed by the default.

The routes above are included in our sample program [here] - which also runs the Flask application with an extra parameter "debug=True"; this replaces the default error messages with something longer and more meaningful ... which will also reveal to a knowledgable user to your site rather more about how the site works if (s)he finds a broken page. You have been warned!

Here's the error that's on the server log (I added a deliberate mistake to cause this):
  192.168.200.42 - - [11/Oct/2015 11:08:09] "GET /arthur HTTP/1.1" 500 -
  Traceback (most recent call last):
    File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1836, in __call__
      return self.wsgi_app(environ, start_response)
    [snip]
  TypeError: greet() takes exactly 2 arguments (1 given)
and here's the display to the user (this is just the top of the page - scroll down for more!)


The routing and more is base on Werkzeug- http://werkzeug.pocoo.org - and the whole comes together with much more in Full Stack Python - http://www.fullstackpython.com/flask.html.
(written 2015-10-11)

 Y307 - The Flask micro webdevelopment framework for Python
  [4527] Hello Flask world / Python web micro framework - (2015-10-11)
  [4529] Flask - calling in the templating engine - (2015-10-11)
  [4530] Requests in Flask - (2015-10-11)
  [4531] Jinja2 - Flask templating - (2015-10-11)
  [4532] Flask - first forms and responses with wtforms - (2015-10-12)
  [4533] Sessions in flask - (2015-10-13)
  [4534] Flask - complete MVC site to navigate around a data set - (2015-10-13)
  [4538] Flask and unittest - hello web app test world - (2015-10-15)
  [4540] Unittest of a Flask application including forms - (2015-10-15)

Back to Hello Flask world / Python web micro framework

Previous and next or Horse's mouth home

Forward to Flask - calling in the templating engine

Routing in Flask
Day trip to Lancaster
What does Tcl do if you try to run a command that is not defined?
Tcl - a new example for data reformatting
Catching failed commands and not crashing the program in Tcl