python basis - binary search

# Binary search 


DEF sort_search (LST, Key): 
    "" " 
        binary search 
    : param lst: an ordered sequence 
    : param key: the key value you're looking for 
    : return: key indexes in the number of columns in 
    " "" 
    Low, High = 0, len (LST) -1 
    the while Low <High: 
        MID = (High + Low) // 2 
        IF LST [MID] <Key: 
            Low = MID +. 1 
        elif LST [MID]> Key: 
            High = MID -. 1 
        the else: 
            return MID 
    return None 


L = [. 1, 2,. 3,. 4,. 5,. 6,. 7,. 8,. 9] 
Print ( 'Key index:', sort_search (L, 80))