python index 自己实现

 1 l = [2,3,4,223,42,56,7,389,586,845,8,894,343,46,345,3556,23,233,45,25,78,456,785,576,344,6,34,563,]
 2 l.sort()
 3 print(l)
 4 def find(l ,aim,key=0):
 5     '''二分法找值
 6     key的关键字是这个新序列的第一个元素在原序列的哪一个位置
 7     mid_index 是新序列的的中值
 8     '''
 9     mid_index =len(l)//2
10     if len(l)<=1 and l[0] != aim:
11         return "silly bi "
12     if l[mid_index]>aim:
13         return find(l[0:mid_index],aim,key=key)
14     elif l[mid_index]<aim:
15         return find(l[mid_index+1:],aim,key=mid_index+key+1)
16     elif l[mid_index] == aim:
17         return mid_index+key
18 
19 print(find(l,363))
20 print(l.index(343))

index转译