Python Multi-Adorner

1. Adorner no parameters: Codego.net

>>> def First (func):

print '%s () was post to first () '%func.func_name

def _first (*args,**kw):

print ' Call the function%s () in _first (). ' %func.func_name

return func (*ARGS,**KW)

Return _first

>>> def second (func):

print '%s () was post to second () '%func.func_name

def _second (*args,**kw):

print ' Call the function%s () in _second (). ' %func.func_name

return func (*ARGS,**KW)

Return _second

>>> @first

@second

def test (): Return ' Hello World '

Test () was post to second ()

_second () is post to first ()

>>> Test ()

Call the function _second () in _first ().

Call the function test () in _second ().

' Hello World '

>>>

In fact it is equivalent to the following code:

Copy the code code as follows:

>>> def Test ():

Return ' Hello World '

>>> Test=second (Test)

Test () was post to second ()

>>> Test

<function _second at 0x000000000316d3c8>

>>> Test=first (Test)

_second () is post to first ()

>>> Test

<function _first at 0x000000000316d358>

>>> Test ()

Call the function _second () in _first ().

Call the function test () in _second ().

' Hello World '

>>>

2. The adorner has parameters:

Copy the code code as follows:

>>> def first (Printresult=false):

def _first (func):

print '%s () was post to _first () '%func.func_name

def __first (*args,**kw):

print ' Call the function%s () in __first (). '%\

Func.func_name

If Printresult:

Print func (*args,**kw), ' #print in __first (). '

Else

return func (*ARGS,**KW)

Return __first

Return _first

>>> def second (printresult=false):

def _second (func):

print '%s () was post to _second () '%func.func_name

def __second (*args,**kw):

print ' Call the function%s () in __second (). '%\

Func.func_name

If Printresult:

Print func (*args,**kw), ' #print in __second (). '

Else

return func (*ARGS,**KW)

Return __second

Return _second

>>> @first (True)

@second (True)

def test ():

Return ' Hello World '

Test () was post to _second ()

__second () is post to _first ()

>>> Test ()

Call the function __second () in __first ().

Call the function test () in __second ().

Hello World #print in __second ().

None #print in __first ().

>>>

As above, the 35th line is output after calling __second (), and __second () calls test () and print test (), and then returns to __first () to proceed with print, and the print statement print is __second ( ) returns the None

It is equivalent to:

>>> def Test ():

Return ' Hello World '

>>> Test=second (True) (test)

Test () was post to _second ()

>>>

>>> Test

<function __second at 0x000000000316d2e8>

>>> Test=first (True) (test)

__second () is post to _first ()

>>> Test

<function __first at 0x0000000003344c18>

>>>

3. Multi-Adorner application:

For example, if you are a project manager, you require that each block of code must have parameter checking Argstype and a responsibility check responsibilityregister, which requires two adorners to supervise this block of code.

#coding =utf-8

Import Os,sys,re

From collections Import Ordereddict

def argstype (*argtypes,**kwtypes):

U ' Argstype (*argtypes,**kwtypes)

options=[(' Opt_usetypeofdefaultvalue ', False)]

The following switches are related to this function, not the keyword parameters associated with type checking, all options:

Opt_usetypeofdefaultvalue=>bool:false, when True, will have a default of the specified type

The value parameter uses the type of its default value

‘‘‘

def _argstype (func):

#确定所有的parameter Name

Argnames=func.func_code.co_varnames[:func.func_code.co_argcount]

#确定所有的default parameter

Defaults=func.func_defaults

If defaults:

Defaults=dict (Zip (Argnames[-len (defaults):],defaults))

Else:defaults=none

#将 all the Options keyword arguments in the parameter type keyword parameter

Options=dict ()

For Option,default in [(' Opt_usetypeofdefaultvalue ', False)]:

Options[option]=kwtypes.pop (Option,default)

#argTypes和kwTypes的总长度应该与argNames一致

If Len (argtypes) +len (kwtypes) >len (argNames):

Raise Exception (' Too much types to check%s (). ' %func.func_name)

#所有kwTypes中的键不能覆盖在argTypes中已经占用的names

If not set (Argnames[len (argtypes):]). Issuperset (

Set (Kwtypes.keys ())):

Raise Exception (' There is some key in Kwtypes ' +

' Which is not in argNames. ')

#确定所有的参数应该有的types

Types=ordereddict ()

For name in Argnames:types[name]=none

If Len (argtypes):

For I in range (len (argtypes)):

Name=argnames[i]

Types[name]=argtypes[i]

Else

For name,t in Kwtypes.items ():

Types[name]=t

If Len (kwtypes):

For name,t in Kwtypes.items ():

Types[name]=t

#关于default the type of parameter

If options[' Opt_usetypeofdefaultvalue ']:

For k,v in Defaults.items ():

#如果default parameter type is not specified otherwise, use the

The type of the default value of the #default parameter

If Types[k]==none:

Types[k]=type (v)

def __argstype (*args,**kw):

#order the Args

Args=ordereddict ()

#init keys

For name in Argnames:args[name]=none

#init Default values

If defaults is not None:

For k,v in Defaults.items ():

Args[k]=v

#fill in all args

For I in range (len (args)):

Args[argnames[i]]=args[i]

#fill in all keyword args

For k,v in Kw.items ():

Args[k]=v

#check If there is some None in the values

If Defaults==none:

For K in Args:

If Args[k]==none:

If Defaults==none:

Raise Exception (('%s () needs%r parameter, ' +

' which is not given ')% (func.func_name,k))

Else

If not Defaults.has_key (k):

Raise Exception (' Parameter%r of%s () is ' +

' Not a default parameter ')%\

(K,func.func_name))

#check All Types

For K in Args:

If not isinstance (Args[k],types[k]):

Raise TypeError (' Parameter%r of%s () must be ' +

' A%r object, but you post:%r ')%\

(K,func.func_name,types[k],args[k]))

return func (*ARGS,**KW)

Return __argstype

Return _argstype

def responsibilityregister (author):

def _responsibilityregister (func):

def __responsibilityregister (*args,**kw):

Try

return func (*ARGS,**KW)

Except Exception as E:

Print ("Something is wrong, It's%s ' s responsibility."%\

Author). Center (80, ' * ')

Raise E

Return __responsibilityregister

Return _responsibilityregister

@ResponsibilityRegister (' Kate ')

@ArgsType (Str,int)

def left (str,len=1):

return Str[:len]

print ' Good calling: '

Print left (' Hello World ', 8)

print ' Bad calling: '

Print left (3,7)

Python Multi-Adorner