Python and the Web
Plone Conference 2016
@brandon_rhodes
The Social Network (2010)
“We don’t even know
what it is yet.”
“We don’t even know
what it is yet.”
Web → ← Python
What does Python offer?
Reflection
Object oriented
Dynamic
Simple
Reflection
A program can see
itself in the mirror
dir()
getattr()
type()
import cherrypy
class HelloWorld(object):
def index(self):
return "Hello World!"
index.exposed = True
views = {}
for name, object in cls.__dict__.items():
exposed = getattr(object, 'exposed', False)
if exposed:
views[name] = object
Object oriented
= subclassing
# "Object based": hides complexity
def monitor():
...
t = threading.Thread(target=monitor)
# "Object oriented": subclassing
class MonitorThread(threading.Thread):
def run(self):
...
Object oriented: you get
invited to write new methods
for existing classes
(And, it eats a level of indentation)
Dynamic
Code objects — modules,
classes, functions — can
change at runtime
What error should this code raise?
# "from framework import request"?
def my_view():
return (
'Hi, you sent {} cookies.'
.format(len(request.cookies))
)
# framework.py
...
# Magically create a global!
views_module.request = Request(...)
...
In a dynamic language,
you can wind up with code and
objects that don’t even exist
in your raw source code
Q: Does it make your
code more readable?
Simple
“Things should be as simple
as possible, but no simpler.”
— Einstein, quoted in
“every company gets about
three innovation tokens”
— Dan McKinley,
“MySQL is boring.
Postgres is boring.
PHP is boring.
Python is boring.”
Q: What makes Python
wonderful for the web?
Reflection
Object oriented
Dynamic
Simple
Q: What makes Python
wonderful for the web?
Reflection
Object oriented
Dynamic
Simple
Django
Flask
Bottle
Pyramid
Morepath
Flask 23,132
Django 21,712
Bottle 4,038
Pyramid 2,122
Morepath 263
Flask 23,132
Django 21,712
Bottle 4,038
Pyramid 2,122
Morepath 263
Flask 23,132
Django 21,712
web.py 4,089
Bottle 4,038
Pyramid 2,122
web2py 1,218
Morepath 263
CherryPy 201
What do the
top frameworks
have in common?
Flask 23,132
Django 21,712
web.py 4,089
Bottle 4,038
⋮
Flask and Django
- Views are plain functions
- Explicit registration (not reflection)
- Your app can start small and grow
- Aim for simplicity
Django
Python’s default first framework
ORM: persist data in a database
Admin interface: database visible
Forms library
Forms library!?
Trade-off: yield control
in return for features
Forms library
- Automatic validation
- Re-fill form for retry
- XSS protection
Flask
The go-to second framework
Will people keep writing
Python for the web?
What’s the competition?
JavaScript
- Language inside every browser
- Web developers already know it
- Node.js brings it to the server
Python — 2 vs 3, C Python vs PyPy
JavaScript — Node.js, ES6 → ES5
Python
reflection
generators
iterators
classes
modules
JavaScript
reflection
generators
iterators
classes
modules
It does now
ES6
reflection
generators
iterators
classes
modules
“Everything that rises
must converge”
JavaScript
> 40 - '30'
JavaScript
> 40 - '30'
10
JavaScript
> 40 - '30'
10
> 40 + '30'
JavaScript
> 40 - '30'
10
> 40 + '30'
"4030"
Python
>>> 40 - '30'
Traceback (most recent call last):
...
TypeError: unsupported operand type(s)
TypeScript
TypeScript → ES5!
JavaScript
- Is a contender
- Gaining features
- Becoming safer
JavaScript
- Is a contender
- Gaining features
- Becoming safer
Dynamic,
High-level,
Open source!
Q
What will happen
to Python?
Python has always
played 2nd fiddle to
some other web language
PHP, VB Script, Ruby, JS
What are Python’s advantages?
Becoming the world’s
default language
Often the language
learned in school
Simple syntax is perfect for
the “occasional programmer”
Burgeoning community
The Web and Python met
when both were immature
Web → ← Python
“We don’t even know
what it is yet.”
“We don’t even know
what it is yet.”
Thank you!
@brandon_rhodes