enumerate+range

 1 li = ["电脑","鼠标垫","u盘","游艇"]
 2
 3 # for key,item in enumerate(li,1):
 4 #     print(key,item)
 5
 6 # inp =  input("请输入商品：")
 7
 8 # inp_num = int(inp)
 9
10 # print(li[inp_num-1])
11
12 # # 输入汉字查索引
13 # inp = input("请输入商品：")
14 # ret = li.index(inp)
15 # print(ret)
16
17 print(range(1,10))
18 for i in range(1,10):
19     print(i)
20 print("------------------")
21 for i in range(1,10,2):
22     print(i)
23 print("------------------")
24 for i in range(10,1,-1):
25     print(i)
26 print("------------------")
27 for i in range(10,1,-2):
28     print(i)
29 print("------------------")
30 for i in range(0,-10,-1):
31     print(i)
32
33 li = ["alex","eire"]
34
35 leee = len(li)
36
37 for i in range(0,leee):
38     print(i,li[i])