函数

闭包函数：内函数使用了外函数的局部变量，并且外函数把内函数返回出来的过程叫闭包，被返回出的函数叫闭包函数

def out(): num = 1 def inner(): print(num) return inner res = out() # res == inner res() def out(): num = 1 def middle(): num1 = 2 print(num) def inner(): print(num1) return inner return middle func = out() res = func() # func() 相当于 middle() res() # res() 相当于 inner()

闭包函数

def out(name): def inner(): print(name,"喜欢在夏天穿短裤") return inner func = out("小明") # func == inner : func() == inner() func()

迭代器：数据量（序列里的数据）过大的情况需要用到迭代器

for i in range(1,100000000000): pass # iter() zip(),生成器的方式 # iter() 功能：把可迭代数据对象 转换为迭代器 # 参数： 可迭代的对象（list,str,tuple,set,dict,range()） # 返回值： 迭代器,是可迭代的对象，但可迭代的对象不一定是迭代器 from collections import Iterator,Iterable str1 = "你好世界" res = isinstance(str1,Iterable) print(res) #Ｔｒｕｅ res1 = isinstance(str1,Iterator) print(res1)# str1 不是迭代器 list1 = [1,2,3,4,5] res = isinstance(list1,Iterable) print(res) #Ｔｒｕｅ res1 = isinstance(list1,Iterator) print(res1)# list1 不是迭代器 # 得到一个迭代器 list1 = [1,2,3,4,5,6,7,8,9,0] res = iter(list1) print(res,type(res)) # str str1 = "北京这块热死了" res = iter(str1) print(res,type(res)) # 从迭代器里取值：三种 # 注意事项：从迭代器里取值，取走一个就少一个，取空之后再取数据的话，就会报错 # 1.使用next() 函数 # tuple tuple1 = (1,2,3,4,5,6) res = iter(tuple1) print(next(res)) print(next(res)) print(next(res)) print(next(res)) print(next(res)) print(next(res)) # print(next(res)) # 2.使用数据类型转换的方式取值 result = list(res) print(result) # 3.使用 for 循环遍历迭代器 for num in res: print(num) result = list(res) print(result) print('--------------------') # 学习一个陌生的函数，学习函数的功能，参数，返回值 # zip(Iterable,Iterable,...) list1 = ["大锤","二妮","小可爱"] tuple1 = ("80","40","白给") res = zip(list1) print(res,type(res)) # 取值 print(next(res)) print(next(res)) print(next(res)) res1 = isinstance(res,Iterator) print(res1) # zip多个参数 list1 = ["大锤","二妮","小可爱","老可爱"] tuple1 = ("80","40","白给") res = zip(list1,tuple1) for name in res: print(name) res1 = dict(res) print(res1) # *zip() # *zip 不能作为开头直接出现，需要和zip 配合使用 list1 = ["大锤","二妮","小可爱","老可爱"] tuple1 = ("80","40","白给") res = zip(*zip(list1,tuple1)) for name in res: print(name)