#1. 判断数据类型是否为可迭代数据类型 In [25]: from collections import Iterable In [26]: isinstance('hello',Iterable) Out[26]: True In [27]: isinstance([1,2,3],Iterable) Out[27]: True In [28]: isinstance(1,Iterable) Out[28]: False In [29]: isinstance({1,2,3},Iterable) Out[29]: True In [30]: isinstance({"name":"fentiao"},Iterable) Out[30]: True In [31]: isinstance((1,2,3),Iterable) Out[31]: True #2. 枚举方法，显示为索引-元素对 shopinfo = [ ('Iphone',1000), ('book',200), ('fentiao',3500) ] for i,v in enumerate(shopinfo): print i,v #3. 在for循环里面引用两个变量 shopinfo = [ ('Iphone',1000), ('book',200), ('fentiao',3500) ] for k,v in shopinfo: print k,v # 4.生成器generator # 1). 列表生成式受到内存的限制，列表容量是有限的； # 2). 列表生成式如果只需要前几个元素，浪费内存空间。 3). 访问生成式: # - for循环 # - g.next()方法 l = [i for i in range(1000)] # 列表生成式 g = (i for i in range(1000)) # 生成器 g.next() for i in g: print i # 4. 手动实现生成器 #定义一函数fib，实现斐波那契数列(Fibonicci): # 1, 1, 2, 3, 5, 8, 13, 21.......... # # def fib(n): # # 执行:fib(3) 输出:1,1,2 # 执行:fib(4) 输出:1,1,2,3 def fib(max): n,a,b = 0,0,1 while n < max: yield b a, b = b, a+b n += 1 for i in fib(4): print i
def hello():
print 'a'
yield 1 print 'b' yield 2 print 'c' yield 3 a = hello() a.next() a.next() a.next() ''' # 通过yield实现单线程的并发运算 # 异步I/O模型epoll http nginx tomcat import time def consumer(name): print '%s 准备吃粉条了!' % (name) while True: fentiao = yield print ('粉条[%s]做出来了，被[%s]吃了') % (fentiao, name) # g = consumer('肖遥') # g.next() # g.send('孜然味') def producer(name): c1 = consumer('肖遥') c2 = consumer('韩窑') c1.next() c2.next() print '开始制作粉条晚餐了........' for i in ['清蒸','油炸','爆炒']: time.sleep(1) print '[%s] 做了两份粉条,两个人一块吃' %(name) c1.send(i) c2.send(i) producer('杨佳晨')
转载请注明原文地址: https://www.6miu.com/read-80801.html
