Scott Ming scottming

Rules for good testing

Look at the following image...

...it shows an object being tested.

You can't see inside the object. All you can do is send it messages. This is an important point to make because we should be "testing the interface, and NOT the implementation" - doing so will allow us to change the implementation without causing our tests to break.

Moved

Now located at https://github.com/JeffPaine/beautiful_idiomatic_python.

Why it was moved

Github gists don't support Pull Requests or any notifications, which made it impossible for me to maintain this (surprisingly popular) gist with fixes, respond to comments and so on. In the interest of maintaining the quality of this resource for others, I've moved it to a proper repo. Cheers!

Recursion

What is recursion?

A recursive function is a function that makes a call to itself.

To prevent infinite recursion, you need at least one branch (i.e. of an if/else statement) that does not make a recursive call. Branches without recursive calls are called base cases; branches with recursive calls are called recursive cases.

def factorial_recursive(n)
 if n == 0

If you have two days to learn the very basics of modelling, Domain-Driven Design, CQRS and Event Sourcing, here's what you should do:

In the evenings read the [Domain-Driven Design Quickly Minibook]{http://www.infoq.com/minibooks/domain-driven-design-quickly}. During the day watch following great videos (in this order):

Eric Evans' [What I've learned about DDD since the book]{http://www.infoq.com/presentations/ddd-eric-evans}
Eric Evans' [Strategic Design - Responsibility Traps]{http://www.infoq.com/presentations/design-strategic-eric-evans}
Udi Dahan's [Avoid a Failed SOA: Business & Autonomous Components to the Rescue]{http://www.infoq.com/presentations/SOA-Business-Autonomous-Components}
Udi Dahan's [Command-Query Responsibility Segregation]{http://www.infoq.com/presentations/Command-Query-Responsibility-Segregation}
Greg Young's [Unshackle Your Domain]{http://www.infoq.com/presentations/greg-young-unshackle-qcon08}
Eric Evans' [Acknowledging CAP at the Root -- in the Domain Model]{ht

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

	package main

	import (
	"fmt"
	)

	func decorator(f func(s string)) func(s string) {

	return func(s string) {
	fmt.Println("Started")

	apt-get install python-pygraphviz
	pip install django-extensions
	# add 'django_extensions' to INSTALLED_APPS in settings.py
	python manage.py graph_models trees -o test.png

	from sklearn import linear_model
	from scipy import stats
	import numpy as np


	class LinearRegression(linear_model.LinearRegression):
	"""
	LinearRegression class after sklearn's, but calculate t-statistics
	and p-values for model coefficients (betas).
	Additional attributes available after .fit()

	from distutils.core import setup
	from distutils.extension import Extension
	from Cython.Distutils import build_ext

	ext_modules = [
	Extension("test_um",
	["test_um.pyx"],
	include_dirs=["/usr/local/include/boost"],
	library_dirs=["/usr/local/lib"],
	language="c++")

	;
	(define (atom? x)
	(and (not (pair? x)) (not (null? x))))

	; consist of atoms
	(define (lat? l)
	(cond
	((null? l) #f)
	((atom? (car l)) (lat? (cdr l)))
	(else #f)))