The use of *args and **kwargs in Python functions to pass variable-length parameters

Reference from: http://www.jb51.net/article/78705.htm

The Single Form (*args) is used to pass a list of non-named key mutable parameters. The binary number form (**kwargs) is used to pass a variable parameter list of key values.

1. A fixed positional parameter and two variable-length parameters are passed.

def Test_var_args (farg, *args):  print"formal arg:", Farg  for in  args:    print"another arg:  ", Arg test_var_args ("A ", 31  3

2. A fixed parameter and two key-value parameters.

defTest_var_kwargs (Farg, * *Kwargs):Print "Formal ARG:", Farg forKeyinchKwargs:Print "Another keyword arg:%s:%s"%(Key, Kwargs[key]) Test_var_kwargs (Farg=1, myarg2=" Both", myarg3=3The result is: formal arg:1another keyword arg:myarg2:twoanother keyword arg:myarg3:3

3. When calling a function, use *args and **kwargs

defTest_var_args_call (arg1, Arg2, ARG3):Print "arg1:", Arg1Print "arg2:", Arg2Print "Arg3:", Arg3 args= (" Both", 3) Test_var_args_call (1, *args) The result is: arg1:1ARG2:TWOARG3:3-------------------------------------------Key-value pair mode:defTest_var_args_call (arg1, Arg2, ARG3):Print "arg1:", Arg1Print "arg2:", Arg2Print "Arg3:", Arg3 Kwargs= {"Arg3": 3,"arg2":" Both"}test_var_args_call (1, * *Kwargs) The result is: arg1:1ARG2:TWOARG3:3

The use of *args and **kwargs in Python functions to pass variable-length parameters