python index 自己实现

 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,]
 l.sort()
 print(l)
 def find(l ,aim,key=0):
     '''二分法找值
     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
     mid_index 是新序列的的中值
     '''
     mid_index =len(l)//2
     if len(l)<=1 and l[0] != aim:
         return "silly bi "
     if l[mid_index]>aim:
         return find(l[0:mid_index],aim,key=key)
     elif l[mid_index]<aim:
         return find(l[mid_index+1:],aim,key=mid_index+key+1)
     elif l[mid_index] == aim:
         return mid_index+key

 print(find(l,363))
 print(l.index(343))

index转译