测试1
deco运行，但myfunc并没有运行
复制代码 代码如下:
def deco(func):
    print 'before func'
    return funcdef myfunc():
    print 'myfunc() called'
myfunc = deco(myfunc)
测试2
需要的deco中调用myfunc，这样才可以执行
复制代码 代码如下:
def deco(func):
    print 'before func'
    func()
    print 'after func'
    return funcdef myfunc():
    print 'myfunc() called'
myfunc = deco(myfunc)
测试3
@函数名 但是它执行了两次
复制代码 代码如下:
def deco(func):
    print 'before func'
    func()
    print 'after func'
    return func@deco
def myfunc():
    print 'myfunc() called'
myfunc()
测试4
这样装饰才行
复制代码 代码如下:
def deco(func):
    def _deco():
        print 'before func'
        func()
        print 'after func'
    return _deco@deco
def myfunc():
    print 'myfunc() called'
myfunc()
测试5
@带参数，使用嵌套的方法
复制代码 代码如下:
def deco(arg):
    def _deco(func):
        print arg
        def __deco():
            print 'before func'
            func()
            print 'after func'
        return __deco
    return _deco@deco('deco')
def myfunc():
    print 'myfunc() called'
myfunc()
测试6
函数参数传递
复制代码 代码如下:
def deco(arg):
    def _deco(func):
        print arg
        def __deco(str):
            print 'before func'
            func(str)
            print 'after func'
        return __deco
    return _deco@deco('deco')
def myfunc(str):
    print 'myfunc() called ', str
myfunc('hello')
测试7
未知参数个数
复制代码 代码如下:
def deco(arg):
    def _deco(func):
        print arg
        def __deco(*args, **kwargs):
            print 'before func'
            func(*args, **kwargs)
            print 'after func'
        return __deco
    return _deco@deco('deco1')
def myfunc1(str):
    print 'myfunc1() called ', str
@deco('deco2')
def myfunc2(str1,str2):
    print 'myfunc2() called ', str1, str2
myfunc1('hello')
myfunc2('hello', 'world')
测试8
class作为修饰器
复制代码 代码如下:
class mydecorator(object):
def __init__(self, fn):
        print inside mydecorator.__init__()
        self.fn = fn
def __call__(self):
        self.fn()
        print inside mydecorator.__call__()
@mydecorator
def afunction():
    print inside afunction()
print finished decorating afunction()
afunction()
测试9
复制代码 代码如下:
class mydecorator(object):
def __init__(self, str):
        print inside mydecorator.__init__()
        self.str = str
        print self.str
def __call__(self, fn):
        def wrapped(*args, **kwargs):
            fn()
            print inside mydecorator.__call__()
        return wrapped
@mydecorator('this is str')
def afunction():
    print inside afunction()
print finished decorating afunction()
afunction()
实例
给函数做缓存 --- 斐波拉契数列
复制代码 代码如下:
from functools import wraps
def memo(fn):
    cache = {}
    miss = object()
@wraps(fn)
    def wrapper(*args):
        result = cache.get(args, miss)
        if result is miss:
            result = fn(*args)
            cache[args] = result
        return result
return wrapper
@memo
def fib(n):
    if n         return n
    return fib(n - 1) + fib(n - 2)print fib(10)
注册回调函数 --- web请求回调
复制代码 代码如下:
class myapp():
    def __init__(self):
        self.func_map = {}
def register(self, name):
        def func_wrapper(func):
            self.func_map[name] = func
            return func
        return func_wrapper
def call_method(self, name=none):
        func = self.func_map.get(name, none)
        if func is none:
            raise exception(no function registered against - + str(name))
        return func()
app = myapp()
@app.register('/')
def main_page_func():
    return this is the main page.
@app.register('/next_page')
def next_page_func():
    return this is the next page.
print app.call_method('/')
print app.call_method('/next_page')
mysql封装 -- 很好用
复制代码 代码如下:
import umysql
from functools import wraps
class configuraion:
    def __init__(self, env):
        if env == prod:
            self.host    = coolshell.cn
            self.port    = 3306
            self.db      = coolshell
            self.user    = coolshell
            self.passwd  = fuckgfw
        elif env == test:
            self.host   = 'localhost'
            self.port   = 3300
            self.user   = 'coolshell'
            self.db     = 'coolshell'
            self.passwd = 'fuckgfw'
def mysql(sql):
_conf = configuraion(env=prod)
def on_sql_error(err):
        print err
        sys.exit(-1)
def handle_sql_result(rs):
        if rs.rows > 0:
            fieldnames = [f[0] for f in rs.fields]
            return [dict(zip(fieldnames, r)) for r in rs.rows]
        else:
            return []
def decorator(fn):
        @wraps(fn)
        def wrapper(*args, **kwargs):
            mysqlconn = umysql.connection()
            mysqlconn.settimeout(5)
            mysqlconn.connect(_conf.host, _conf.port, _conf.user, \
                              _conf.passwd, _conf.db, true, 'utf8')
            try:
                rs = mysqlconn.query(sql, {})     
            except umysql.error as e:
                on_sql_error(e)
data = handle_sql_result(rs)
            kwargs[data] = data
            result = fn(*args, **kwargs)
            mysqlconn.close()
            return result
        return wrapper
return decorator
@mysql(sql = select * from coolshell )
def get_coolshell(data):
    ... ...
    ... ..
线程异步
复制代码 代码如下:
from threading import thread
from functools import wraps
def async(func):
    @wraps(func)
    def async_func(*args, **kwargs):
        func_hl = thread(target = func, args = args, kwargs = kwargs)
        func_hl.start()
        return func_hl
return async_func
if __name__ == '__main__':
    from time import sleep
@async
    def print_somedata():
        print 'starting print_somedata'
        sleep(2)
        print 'print_somedata: 2 sec passed'
        sleep(2)
        print 'print_somedata: 2 sec passed'
        sleep(2)
        print 'finished print_somedata'
def main():
        print_somedata()
        print 'back in main'
        print_somedata()
        print 'back in main'
main()