利用生成器和闭包返回递增计数器

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#1 Created at ... [Delete] [Delete and Lock User]

def createCounter():

# 定义生成器
def f():
    n = 1
    while True:
       yield n
       n += 1

# 返回函数      
gen = f()
def counter():
    return next(gen)

return counter

#2 Created at ... [Delete] [Delete and Lock User]

方法二：

def createCounter(): x = [0] def counter(): x[0] += 1 return x[0]
return counter

方法三：

def createCounter(): x = 0
def counter(): nonlocal x x += 1 return x
return counter

nonlocal关键字使得闭包中内部函数可以访问和修改外部函数中定义的局部变量x，奇妙的是当x是列表时并不需要使用该关键字

#3 Created at ... [Delete] [Delete and Lock User]

第二种方法中：x指向了一个list，类似于元组中套用list，指向是不变的，但是list内容可以被函数内部的第二层函数改变

#4 Created at ... [Delete] [Delete and Lock User]

test

#5 Created at ... [Delete] [Delete and Lock User]

#6 Created at ... [Delete] [Delete and Lock User]

Iterator和是闭包函数的一种吗?

#7 Created at ... [Delete] [Delete and Lock User]

利用生成器 ---这种方法算闭包吗？

#8 Created at ... [Delete] [Delete and Lock User]

def createCounter(): def counter(sum = [0]): sum[0] += 1 return sum[0] return counter

整那么多，花里胡哨的

#9 Created at ... [Delete] [Delete and Lock User]

nonlocal关键字使得闭包中内部函数可以访问和修改外部函数中定义的局部变量x，奇妙的是当x是列表时并不需要使用该关键字

为什么。