• *args is used when we want to send an arbitrary number of non-keyworded inputs to the function. The inputs are packed into a tuple inside the function.

• **kwargs is used when we want to send an arbitrary number of keyworded inputs to a function. The inputs are packed into a dictionary inside the function.

• They can be used in one function at the same time as well.

• . The main functionality is driven by the asterisk * ; args and kwargs are just names. They are used by convention.

  • function work 是因為有*** 星字號 決定** ; args / kwargs 是慣用法 _ 把args 改成anything 也可以

• . Function input definition order should be

  • (1) normal parameters,
  • (2) default parameters,
  • (3) *args,
  • (4) **kwargs

• Arbitrary Number of Arguments : 訂定一個function 可以給定 “ 位意” 數量 input / arguement

  • • args 送 none-keyword (input 會被包到一個tuple 中)
  • ** kwargs 送 keyword input 包到一個dictionary 中)

def sum(*args):
    print(args)
    print(type(args))  # print args type

sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
------------------------------------------
(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
<class 'tuple'>

def sum(*args):

    # sum 加法如何計算
    result = 0
    for number in range(0, len(args)):
        print(f"we are now at number {number}") 
        print(f"also args[number] is {args[number]}")
        result += args[number]
        print(f"now the result is {result}")

    return result

sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

---------------------------------------

we are now at number 0
also args[number] is 1
now the result is 1
we are now at number 1
also args[number] is 2
now the result is 3
we are now at number 2
also args[number] is 3
now the result is 6
we are now at number 3
also args[number] is 4
now the result is 10
we are now at number 4
also args[number] is 5
now the result is 15
we are now at number 5
also args[number] is 6
now the result is 21
we are now at number 6
also args[number] is 7
now the result is 28
we are now at number 7
also args[number] is 8
now the result is 36
we are now at number 8
also args[number] is 9
now the result is 45
we are now at number 9
also args[number] is 10
now the result is 55

# **kwargs 

def myfunc(**kwargs):
    print(kwargs)
    print(type(kwargs))
    print(" {} now live in {} city" .format(kwargs["name"], kwargs["city"]))

myfunc(name="albert", gender="male", city="Taoyuan")

---------------------------

{'name': 'albert', 'gender': 'male', 'city': 'Taoyuan'}
<class 'dict'>
albert now live in Taoyuan city