def Seach(alist,tem): # 有序的二分搜索
    if len(alist) == 0:
        return False
    else:
        half = len(alist) // 2
        if alist[half] == tem:
            return True
        else:
            if alist[half] > tem:
                return Seach(alist[:half],tem)
            elif alist[half] < tem:
                return Seach(alist[half+1:],tem)
alist = [1,2,5,8,9,10,21,22,23,33]
print(Seach(alist,9))