Python学习基础（三）——装饰器，列表生成器，斐波那契数列

装饰器——闭包

# 装饰器  闭包

'''

    如果一个内部函数对外部（非全局）的变量进行了引用，那么内部函数被认为是闭包

    闭包 = 函数块  +  定义时的函数环境

'''

def f():
    x = 100
    y = 200

    def mytext():
        return x + y

    return mytext


s=f()
print(s())

 

装饰器——高潮1

import time


def foo():
    print("foo..........")
    time.sleep(2)


def root():
    print("root---------")
    time.sleep(1)


def get_time(h):
    start = time.time()
    h
    stop = time.time()
    print("运行时间为: %s" % (stop - start))


get_time(root())

 

装饰器——高潮2

import time

def get_time(h):
    def inner():
        start = time.time()
        h()
        stop = time.time()
        print("运行时间为: %s" % (stop - start))

    return inner


@get_time
def foo():
    print("foo..........")
    time.sleep(2)


@get_time
def root():
    print("root---------")
    time.sleep(1)


foo()

 

装饰器——函数功能添加参数

import time


def get_time(f):
    def inner(*s):
        start = time.time()
        f(*s)
        end = time.time()
        print("使用时长为: %s" % (end - start))

    return inner


@get_time
def add(*a):
    sum = 0
    for i in a:
        sum += i;
    print(sum)
    time.sleep(2)


add(2, 3, 5, 7)

 

列表生成式

# 列表生成式
a = [x * x for x in range(10)]
print(a)

 

列表生成器

# 列表生成器

s = (x * 2 for x in range(5))
# print(s)

# print(s.__next__())
print(next(s))

print(next(s))
print(next(s))
print(next(s))
print(next(s))

print("*-*--**--*--*-*-*-*---*")


def foo():
    print("ok1")
    yield 1
    print("ok2")
    yield 2


g = foo()
# next(g)
# next(g)
for i in g:
    # while True:
    #     i = next(foo())
    print(i)
print("/*//***/*/***//*/**/*")

a = [1, 2, 3]

 

斐波那契数列

def fib(m):
    i, a, b = 0, 0, 1
    while i < m:
        print(b)
        a, b = b, a + b
        i += 1


# fib(10)


z = 10
c = 20

print("------------")

z, c = c, z + c

print(z)
print(c)

print("*************")

z = 10
c = 20

z = c
c = z + c

print(z)
print(c)

print("-------------")