作者:欣欣然人人宇 | 来源:互联网 | 2017-05-14 02:44
1、enum#!usrbinenvpython#-*-coding:utf-8-*-defenum(**enums):returntype(Enum,(),enums)Genderenum(MALE0,FEMALE1)printGender.MALEprintGender.FEMALE2、检查字符串是否是number...
1、enum
Python代码
#!/usr/bin/env python
# -*- coding:utf-8 -*-
def enum(**enums):
return type('Enum', (), enums)
Gender = enum(MALE=0,FEMALE=1)
print Gender.MALE
print Gender.FEMALE
2、检查字符串是否是number
Python代码
s='123456789'
s.isdigit()#return True
3、list取交集
Python代码
s=[1,2,3]
w=[2,3,4]
list(set(s).intersection(w))
4、两个list转成一个dict
Python代码
dict(zip(a,b))
5、singleton
Python代码
def singleton(cls):
instances = {}
def get_instance():
if cls not in instances:
instances[cls] = cls()
return instances[cls]
return get_instance
第二种tornado IOLoop中使用的单例模式:
Python代码
@staticmethod
def instance():
"""Returns a global IOLoop instance.
Most single-threaded applications have a single, global IOLoop.
Use this method instead of passing around IOLoop instances
throughout your code.
A common pattern for classes that depend on IOLoops is to use
a default argument to enable programs with multiple IOLoops
but not require the argument for simpler applications::
class MyClass(object):
def __init__(self, io_loop=None):
self.io_loop = io_loop or IOLoop.instance()
"""
if not hasattr(IOLoop, "_instance"):
with IOLoop._instance_lock:
if not hasattr(IOLoop, "_instance"):
# New instance after double check
IOLoop._instance = IOLoop()
return IOLoop._instance
6、list排重
Python代码
{}.fromkeys(list).keys()