迭代器操作函数的使用

笔记 lst = [54, 56, 77, 4, 567, 34] # (1)排序操作 asc_lst = sorted(lst) # 升序 desc_lst = sorted(lst, reverse=True) # 降序 print('原列表：', lst) print('升序：', asc_lst) print('降序：', desc_lst) # (2)reversed 反向 new_lst = reversed(lst) print(type(new_lst)) # <class 'list_reverseiterator'> 迭代器对象 print(list(new_lst)) # (3)zip x = ['a', 'b', 'c', 'd'] y = [10, 20, 30, 40, 50] zipobj = zip(x, y) print(type(zipobj)) # <class 'zip'> # print(list(zipobj)) # enumerate enum = enumerate(y, start=1) print(type(enum)) # <class 'enumerate'> print(tuple(enum)) # (5)all lst2 = [10, 20, '', 30] print(all(lst2)) # False,空字符串的布尔值是False print(all(lst)) # True # (6)any print(any(lst2)) # True # (7) print(next(zipobj)) # ('a', 10) print(next(zipobj)) print(next(zipobj)) def fun(num): return num % 2 == 1 # 可能是True,False obj = filter(fun, range(10)) # 将range(10),0-9的整数，都执行一次fun操作 print(list(obj)) # [1, 3, 5, 7, 9] def upper(x): return x.upper() new_lst2=['hello','world','python'] obj2=map(upper,new_lst2) print(list(obj2))