Python的可變長度參數*和**，傳參序列解包，isinstance的使用

import math
def f1(*argu):
    print(argu)
def f2(**argu):
    for i in argu.items():
        print(i)        
print("可變長度參數*和**".center(40, '-'))
f1(1,2,3,4,5)
f2(a=1,b=2,c=3)
print("傳參序列解包".center(40,'-'))
def f3(a,b,c):
    print(a*b*c)
seq=[1,2,3]
dic={'a':2,'b':3,'c':4}
f3(*seq)
f3(**dic)
print("isinstance的使用".center(40,'-'))
def circleArea(r):
    if isinstance(r, (int,float)) and r>0:
        print(math.pi*r*r)
    else:
        print("You must give an integer or float as radius!")
circleArea(5)