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 func def myfunc():print 'myfunc() called'myfunc = deco(myfunc)测试2立即学习“Python免费学习笔记（深入）
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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 func def 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 Python 3.14.3微软官方的 Python 扩展，是 VS Code 安装量最高的扩展（209M+）。集成 IntelliSense（通过 Pylance）、调试（通过 Python Debugger）、代码检查、格式化、重构和单元测试等功能。支持 Jupyter Notebook、虚拟环境管理和多 Python 版本切换。
下载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):... ...
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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()