python语法错误

Question

def binary_search(list,item):
    low=0
    high=len(list)-1
    while low<=high:
        mid=(low+high)/2
        guess=list[mid]
        if guess==item:
            return mid
        if guess<item:
            return low=mid+1
        else:
            return high=mid-1
    return None
my_list=[1,3,5,7,9]
binary_search(my_list,-1)

File "<ipython-input-6-b0d18351752a>", line 10
    return low=mid+1
              ^
SyntaxError: invalid syntax
显示语法错误到底哪里错误啊

Answer 1

return 错误，应该写为

return mid+1
//或者
low = mid + 1
return low

修改之后运行依然报错，TypeError: list indices must be integers or slices, not float

list的索引不能为float，

print(type((low + high) / 2))输出查看类型

<class 'float'>显示为float类型

进行修改

mid=int((low+high)/2)强制转换为int类型