概念有很多，这里就不详细介绍了，提供一个连接：https://blog.csdn.net/Mac_timmy/article/details/75712146

import random

def guess():
    count=1
    realNumber = random.randint(1, 200)
    while True:
        guessNumber = int(input("请输入："))
        if guessNumber<realNumber:
            count+=1
            print("太小了！")
        elif guessNumber>realNumber:
            print("太大了！")
            count += 1
        else:
            print("你猜对了噢！一共猜了",count,"次！")
            break

#二分查找
def binary_search(list,item):
    low = 0
    high = len(list)-1
    while low <= high:
      mid = int((low + high)/2)
      guess = list[mid]
      if guess > item:
          high = mid -1
      elif guess < item:
          low = mid + 1
      else:
          return mid
    return None


if __name__=="__main__":
     #guess()
     list=[1,2,3,4,5,6,7,8,9,10]
     print(binary_search(list,7))

参考：https://blog.csdn.net/Mac_timmy/article/details/75712146