■ 闭包特性

■ 简单闭包

def outer(logo):

    def inner(msg):
        print(f"<{logo}>{msg}<{logo}>")

    return inner

fn1 = outer("程序员")
fn1("大家好")
fn1("大家好")

■ 使用nonlocal关键字修改外部函数的值

fn2 = outer("大学教育")
fn2("大家好")
# 使用nonlocal关键字修改外部函数的值
def outer(num1):

    def inner(num2):
        nonlocal num1
        num1 += num2
        print(num1)

    return inner

fn = outer(10)
fn(10)
fn(10)
fn(10)
fn(10)

■ 使用闭包实现ATM小案例

def account_create(initial_amount=0):

    def atm(num, deposit=True):
        nonlocal initial_amount
        if deposit:
            initial_amount += num
            print(f"存款：+{num}， 账户余额：{initial_amount}")
        else:
            initial_amount -= num
            print(f"取款：-{num}， 账户余额：{initial_amount}")

    return atm

atm = account_create()

atm(100)
atm(200)
atm(100, deposit=False)