Python in Parameter *args, **kwargs

Python in Parameter *args, **kwargs

def foo (*args, * *Kwargs):
print 'args = ', args
print 'kwargs = ', kwargs
print '---------------------------------------'

if __name__ = = ' __main__ ':
Foo (1,2,3,4)
Foo (a=1,b=2,c=3)
Foo (1,2,3,4, a=1,b=2,c=3)
Foo (' A ', 1, None, a=1, b= ' 2 ', c=3) outputs the result as follows:

args  =  (1, 2, 3, 4)  
Kwargs  =  {} 

args  =  ()  
Kwargs  =  {' A ': 1, ' C ': 3, ' B ': 2} 

args  =  (1, 2, 3, 4)  
Kwargs  =  {' A ': 1, ' C ': 3, ' B ': 2} 

Strong>args  =  (' A ', 1, None)  
Kwargs  =  {' A ': 1, ' C ': 3, ' B ': ' 2 '}

As you can see, these two are mutable parameters in Python . *args represents any number of nameless parameters, it is a tuple;**Kwargs represents the keyword parameter, it is a dict. And when using both the *args and * *Kwargs , theargs parameter must be listed before the * *Kwargs , like foo (a=1, b= ' 2 ', c=3, a ', 1, None,) If this is called, the syntax error "Syntaxerror:non-keyword arg after keyword ARG" will be prompted.

-------------------------------------------------------------------------------------------here to see the code for GitHub online:

DefLayerOp:
    "Decorator for composable network layers."

 DefLayer_decorated (Self,*args,**kwargs):
 # automatically set a name if not provided.
Name=Kwargs.setdefault (' Name ',Self.get_unique_name (Op.__NAME__))
 # figure out the layer inputs.
 IfLenSelf.terminals)==0:
 RaiseRuntimeError (' No input variables found for layer%s. '% name)
 ElifLenSelf.terminals)==1:
Layer_input=self.terminals[0]
 Else:
Layer_input=ListSelf.terminals)
 # Perform The operation and get the output.
Layer_output=OpSelf, Layer_input,*Args,**Kwargs)
 # Add to layer LUT. 
  self.layers[name] = layer_output 
 # This output was now the input for the next layer. 
  self.feed (layer_output) 
 # Return self for chained calls. 
  return self 
  
  return layer_decorated 
 
 Reference: 
 http:/ /blog.csdn.net/anhuidelinger/article/details/10011013 
 
        
Go on

python @ usage

def funA(arg):    print ‘A‘    a=arg()@funAdef funB():    print ‘B‘


Here @ equivalent to Funa (Funb ())

The main motivation behind the adorner stems from the Python object-oriented programming, which is a decoration on the function call, which is only applied when a function or method is declared.
The adorner's syntax begins with @, followed by the name of the adorner Korean and optional parameters. Following the adorner, the modified function is declared, and the optional parameter of the modifier

Python in Parameter *args, **kwargs