BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(file)))

SECRET_KEY = '(5hjjo=-=r1s43d+=yu(ay2vy_pe53ut0kzd5skzxa9@5#qf_x'

# SECURITY WARNING: don't run with debug turned on in production!

DEBUG = True

ALLOWED_HOSTS = []

# Application definition

INSTALLED_APPS = [

  'django.contrib.admin',

  'django.contrib.auth',

  'django.contrib.contenttypes',

  'django.contrib.sessions',

  'django.contrib.messages',

  'django.contrib.staticfiles',

  'helloapp',

]

OPTIONS={}

def register_option(name):

  return OPTIONS.setdefault(name,1<<len(OPTIONS))#bin(len(OPTIONS))查看二进制数据 

def has_option(options,name):

  return bool(options&name)

#定义标签

BLUE=register_option('BLUE')

RED=register_option('RED')

YELLOW=register_option('YELLOW')

#设置标签

SET=BLUE|RED

#判断标签是否存在设置中

has_option(SET,BLUE)

has_option(SET,YELLOW)

class Base(object):

  def __secret(self):

    print("don't tell")

  def public(self):

    self.__secret()

class Top(Base):

  def __secret(self):

    print("never say never")

print(dir(Base))

b=Base()

b._Base__secret()

print(dir(Top))

Top().public()

#输出

['_Base__secret',..., 'public']

don't tell

['_Base__secret', '_Top__secret', ..., 'public']

don't tell

def __init__(self):

  pass

def __add__(self):

  pass

is_life=True#是否活着

is_connected=True#是否连接 

has_cache=True#是否有内存

users=['zhangsan','lisi']

persons_addresses={'zhangsan':'beijing','lisi':'shanghai'}