EdisonChendi

# coding=UTF-8

a = "s"
b = "s"
print(id(a)) # python use string interning for short strings
print(id(b))
assert a is b
assert a == b

c = "x" * 100

EdisonChendi

# coding=UTF-8

i = 1
++i # <==> +(+i), no ++ operator in Python
assert i == 2 # AssertionError

EdisonChendi

# coding=UTF-8

# for...else...
def printPrime1(n):
    for i in xrange(2, n):
        found = False
        for j in xrange(2, i):
            if i % j == 0:
                found = True
                break

EdisonChendi

# coding=UTF-8

def lost_exception():
    while True:
        try:
            print("hello world")
            raise IndexError("rrr")
        except NameError as e:
            print 'NameError happened'
            print e

EdisonChendi

# coding=UTF-8

class User(object):

    def __init__(self, id):
        self.id = id

    def __nonzero__(self):
        return self.id not in (None, 0)

EdisonChendi

# coding=UTF-8

def append(newitem, l = []):
    l.append(newitem)
    print(l)

print(append.func_defaults) # []
append(10)
print(append.func_defaults) # [10]
append(20)

EdisonChendi

# coding=UTF-8

class Engineer(object):

    def __init__(self, name, specialty):
        self.name = name
        self.specialty = specialty

    def __repr__(self):
        # __repr__ is for developers

EdisonChendi

# coding=UTF-8
import types

# multi-line string
def multi_line_str():
    s = ('select * '
         'from atable '
         'where afiled="value"')
    print(s)

EdisonChendi

# coding=UTF-8

import operator
engineers = [{"name": "John", "age": 28}, {"name": "Peter", "age": 20}, {"name": "Paul", "age": 33}]
engineers_sorted_by_age = sorted(engineers, key=operator.itemgetter("age"))
print(engineers_sorted_by_age)
print(engineers)
engineers.sort(key=operator.itemgetter("age"), reverse=True)
print(engineers)

EdisonChendi

// https://github.com/hugeen/burst/blob/master/core/event.js
// http://stackoverflow.com/questions/29413222/what-are-the-actual-uses-of-es6-weakmap
// the main strength of WeakMap is that it does not interfere with garbage collection given that they do not keep a reference
var listenableMap = new WeakMap();


export function getListenable (object) {
    if (!listenableMap.has(object)) {
        listenableMap.set(object, {});
    }