Summary of knowledge about variable length parameters in Python functions

#When defining function parameters, you can add * in front of formal parameters, which will obtain all position arguments
#It saves all arguments in a tuple
def fn(*args):
    print("args=", args)
    print("args type:", type(args))


#Parameters with * and other parameters
def fn1(a, b, *args):
    print(a)
    print(b)
    print(args)


#The following two methods can be used, but attention should be paid to when passing arguments
def fn2(*args, a, b):
    print(a)
    print(b)
    print(args)


def fn3(a, *args, b):
    print(a)
    print(args)
    print(b)


if __name__ == "__main__":
    #Receive all position parameters
    fn(1, 2, 3, 4, 5)
    fn1(11, 12, 13, 14)
    #FN2 (21, 22, 23, 24) \
    fn2(21, 22, a=23, b=24)
    #FN3 (21, 22, 23, 24) \
    fn3(21, 22, 23, b=24)

#Formal parameters with * can only receive location parameters, but keyword parameters cannot
#An error will be reported if FN passes the following values
def fn(*args):
    print("args=", args)
    print("args type:", type(args))

if __name__ == "__main__":
    #The message will be saved. Args cannot receive keyword parameters
    fn(1, 2, 3, 4, a=10)

#* * formal parameters can receive keyword parameters
#It saves all received keyword parameters in a dictionary
def fn4(**kwargs):
    print("kwargs = ", kwargs)
    print(type(kwargs))

if __name__ == "__main__":
    fn4(a=1, b=2, c=3)