代码：

def fun1():
    print("hello")
    
def fun2(str):
    str += "!"
    return str
 
def fun3(str="hello!"):
    print(str)
 
def fun4(str1, str2=":", *args):
    print(str1+str2, args)
 
 
if __name__ == '__main__':
    fun1()
    str = fun2("hello")
    print(str)
    fun3("hi!")
    fun3()
    fun4("num",":", 1,2,3,4,5
 

运行结果：

hello
hello!
hi!
hello!
num: (1, 2, 3, 4, 5)