def func():
    msg = '111'
    def func1():
        print(msg)
    return func1
 
"""
1-理解閉包
閉包即內(nèi)部函數(shù)調(diào)用外部函數(shù)作用域里面的變量
比如func1就是一個閉包函數(shù)
"""
func()()# 這里實際上是func1()

"""
2-裝飾器
fn是被裝飾的目標函數(shù)
2.1-僅僅只是傳遞函數(shù)名的裝飾器[基本不會用到]
2.2-裝飾帶有參數(shù)的函數(shù)
2.3-裝飾帶有返回值的函數(shù)
2.4-裝飾參數(shù)不確定的函數(shù)[可歸類到裝飾帶有參數(shù)的函數(shù)里面]
2.5-裝飾器本身攜帶參數(shù)
"""

def decorator(fn):
    def wrapper():
        print("添加的功能,裝飾不帶有參數(shù)的函數(shù)")
        return fn()
    return wrapper
 
@decorator
def test():
    print("原有功能")
 
 
test()# 實際上是decorator(test)
 
def decorator1(fn):
    def wrapper(n1,n2):
        print("添加的功能，裝飾帶有參數(shù)的函數(shù)")
        return fn(n1,n2)
    return wrapper
 
@decorator1
def test1(a,b):
    print("a+b=%s"%(a+b))
    print("原有功能")
 
 
test1(1,2)# 實際上是decorator1(test1(1,2))
 
def decoretor2(fn):
    def wrapper():
        print("添加的功能，裝飾帶有返回值的函數(shù)")
        res = fn()
        return res
    return wrapper
 
@decoretor2
def test2():
    print("原有功能")
    return "返回值001"
 
a = test2() # 實際是decorator2(test2)
print(a)
 
 
def decorator3(fn):
    def warpper(*args,**kwargs):
        print("添加的功能，裝飾不定長參數(shù)的函數(shù)")
        return fn(*args,**kwargs)
    return warpper
 
@decorator3
def test3(n1,n2,n3):
    print("原有功能")
    print(n1+n2+n3)
 
 
test3(1,2,3)# 實際上是decorator1(test1(1,2,3))
 
def decorator4(home):
    def func_1(fn):
        def wrapper(*args,**kwargs):
            print("裝飾器本身攜帶參數(shù)")
            print("目前家在%s"%(home))
            return fn(*args,**kwargs)
        return wrapper
    return func_1
 
@decorator4(home='wuhan')
def test4(n1,n2,n3):
    print("原有功能")
    print(n1+n2+n3)
 
# test3(1,2,3)=decorator3(home="武漢")(test(1,2,3))()
"""
1-先調(diào)用decorator3(home="wuhan")
2-執(zhí)行func_1(test(1,2,3)) # 到這里其實就和前面的裝飾器一樣
3-執(zhí)行wrapper
4-執(zhí)行test(1,2,3)
"""
test4(1,2,3)

def func(a,b,c)
?? ?print(a,b,c)
alist = [1,2,3] # 這里alist的長度必須和函數(shù)中參數(shù)的個數(shù)相同，否則會報錯
func(*alist) ?? ?# 等同于 func(1, 2, 3)
1 2 3

def func(a, b, c):
? ? print(a, b, c)
? ??
if __name__ == "__main__":
? ? dic = {'b': 2, 'c': 3}
? ? func(1, b=2, c=3)
? ? func(1, **dic)
1 2 3
1 2 3

def this_fun(a,b,*args,**kwargs):
?? ?"""
?? ?在這個函數(shù)定義中,參數(shù)”a, b”代表”常規(guī)參數(shù)列表”。
?? ?args 接收元組作為位置參數(shù)，而非是常見的參數(shù)列表
?? ?
?? ?"""
? ? print(a,b)
? ? print(args)
? ? print(kwargs)
if __name__ = '__main__'
?? ?this_fun(0,1,2,3,index1=11,index2=22)
?? ?
0,1
(2, 3)
{'index2': 22, 'index1': 11}

class Model(object):
? ? def __init__(self, name):
? ? ? ? self.name = name
? ? def save(self, force_update=False, force_insert=False):
? ? ? ? if force_update and force_insert:
? ? ? ? ? ? raise ValueError("Cannot perform both operations")
? ? ? ? if force_update:
? ? ? ? ? ? print("Updated an existing record")
? ? ? ? if force_insert:
? ? ? ? ? ? print("Created a new record")

class ChildModel(Model):
? ? def save(self, *args, **kwargs):
? ? ? ? if self.name == 'abcd':
? ? ? ? ? ? super(ChildModel, self).save(*args, **kwargs)
? ? ? ? else:
? ? ? ? ? ? return None

c=ChildModel('abcd')
c.save(force_insert=True)
c.save(force_update=True)
# 結(jié)果
Created a new record
Updated an existing record

def my_sum(*args):
?? ?res = 0
?? ?for val in args:
?? ??? ?res += val
?? ?return res
?? ?
l1 = [4, 8]
l2 = [1,2,3]
print(my_sum(*l1)) ?? ??? ?# 12
print(my_sum(*l2)) ?? ??? ?# 6
print(my_sum(4,5,6)) ?? ?# 15