Test 1
Deco runs, but MyFunc does not run
Copy the Code code as follows:
def deco (func):
print ' before Func '
return func
Def myfunc ():
print ' MyFunc () called '
MyFunc = Deco (MyFunc)
Test 2
Need to call MyFunc in Deco in order to execute
Copy the Code code as follows:
def deco (func):
print ' before Func '
Func ()
print ' after Func '
return func
Def myfunc ():
print ' MyFunc () called '
MyFunc = Deco (MyFunc)
Test 3
@ Function name but it executes twice.
Copy the Code code as follows:
def deco (func):
print ' before Func '
Func ()
print ' after Func '
return func
@deco
Def myfunc ():
print ' MyFunc () called '
MyFunc ()
Test 4
It's a decoration.
Copy the Code code as follows:
def deco (func):
Def _deco ():
print ' before Func '
Func ()
print ' after Func '
Return _deco
@deco
Def myfunc ():
print ' MyFunc () called '
MyFunc ()
Test 5
@ with parameters, using nested methods
Copy the Code code as follows:
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 ()
Test 6
function parameter passing
Copy the Code code as follows:
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 ')
Test 7
Unknown number of parameters
Copy the Code code as follows:
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 ')
Test 8
Class as Decorator
Copy the Code code as follows:
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 ()
Test 9
Copy the Code code as follows:
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 ()
Instance
To cache a function---Fibonacci sequence
Copy the Code code as follows:
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 < 2:
return n
return fib (n-1) + fib (n-2)
Print FIB (10)
Registering a callback function---Web request callback
Copy the Code code as follows:
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 Package--Very useful
Copy the Code code as follows:
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):
... ...
... ..
Thread Async
Copy the Code code as follows:
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 ()
