闭包函数：

# 用闭包函数计算当x=20，y=200，z=1000时，fun1=x + 2*y + 3*z的函数值
def a(x):
    def b(y):
        def c(z):
            return x + 2*y + 3*z
        return c
    return b
print(a(20)(200)(1000))

# 用闭包函数计算一元一次线性方程的值
def line_conf(a, b):
    def line(x):
        return a*x + b
    return line

line1 = line_conf(1, 1)
line2 = line_conf(4, 5)
print(line1(5))
print(line2(5))
print(line_conf(2,3)(5))

#定义一个函数
def test(number):

    #在函数内部再定义一个函数，并且这个函数用到了外边函数的变量，那么将这个函数以及用到的一些变量称之为闭包
    def test_in(number_in):
        print("in test_in 函数, number_in is %d"%number_in)
        return number+number_in
    #其实这里返回的就是闭包的结果
    return test_in


#给test函数赋值，这个20就是给参数number
test_in = test(20)
print(id(test_in))
print(id(test))

#注意这里的100其实给参数number_in
print(test_in(100))

#注意这里的200其实给参数number_in
print(test_in(200))

print(test(20)(200))

def counter(start=0):
    def incr():
        nonlocal start
        start += 1
        return start
    return incr

c1 = counter(5)
print(c1())
print(c1())

c2 = counter(50)
print(c2())
print(c2())

print(c1())
print(c1())

print(c2())
print(c2())

def counter(start=0):
    count=[start]
    def incr():
        count[0] += 1
        return count[0]
    return incr

c1 = counter(5)
print(c1())#6
print(c1())#7
c2 = counter(100)
print(c2())#101
print(c2())#102

def counter(start=0):
    def addone():
        nonlocal start
        start += 1
        return start
    return addone

c1 = counter(0)
print(c1())
print(c1())
print(c1())
print(c1())