python中两个参数的意义 *args **kwargs

We often encounter these two parameters.

First *args

This a list of parameters that without name. Baiclly, it is a tuple.

It accepts more than one parameters.

It's like Java.  

eg in Java:

class HelloWorld(Object ...name):
      public static void main(String[] args){
            System.out.println(name[0].toString())
    }
}

eg:

def test(*args):

　　for i in args:

　　　　print i
test(1,2,3)

Result: you will get 1 2 3

Second **kwargs  keyword 

This is a dict with name.

eg:

def kwargs_test(**kwargs):
    for key, value in kwargs.iteritems():
        print "%s = %s" % (key, value)


kwargs_test(first_name = "jason", last_name = "zhang")

def kwargs_list_test(**kwargs):
    
    print "1--{0}, 2--{1}, 3--{2}".format(a, b, c)


par = ['a', 'b', 'c']

kwargs_list_test(*par)