python 关于**kwargs的使用

在定义函数时，使用**kwargs可以传入多个参数，**kwargs只是个代词，例如

def fun(a, **kwargs):
    print "a is", a
    print "We expect kwargs 'b' and 'c' in this function"
    print "b is", kwargs['b']
    print "c is", kwargs['c']
fun(1, b=3, c=5)

会输出

a is 1                  
We expect kwargs 'b' and 'c' in this function
b is 3
c is 5