3.裝飾器與閉包

###剛剛遇到裝飾器與閉包問題，這個有個小區分

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• 閉包一

def count_outter():
    L = []
    def count_inner():
        for i in range (1,5):
            L.append(i)
        return L
    return count_inner

a = count_outter()
print(a)
print(a())

結果
<function count_outter.<locals>.count_inner at 0x10137a9d8>
[1, 2, 3, 4]

• 閉包二

def count():
    fs = []
    for i in range(1, 4):
        def f():
             return i*i
        fs.append(f)
    return fs

f1, f2, f3 = count()

結果
>>> f1()
9
>>> f2()
9
>>> f3()
9

• 閉包三

def count():
    def f(j):
        def g():
            return j*j
        return g
    fs = []
    for i in range(1, 4):
        fs.append(f(i)) # f(i)馬上被執行，所以i的當前值被傳入f()
    return fs

結果
>>> f1, f2, f3 = count()
>>> f1()
1
>>> f2()
4
>>> f3()
9

• 裝飾器一

import functools

def log(func):
    @functools.wraps(func)
    def wrapper(*args, **kw):
        print('call %s():' % func.__name__)
        return func(*args, **kw)
    return wrapper

• 裝飾器二：帶參裝飾器

import functools

def log(text):
    def decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kw):
            print('%s %s():' % (text, func.__name__))
            return func(*args, **kw)
        return wrapper
    return decorator

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####資料來自廖老師的教程