索引错误问题

Question

所以我正在制作一个计算器，它接收一个字符串并检查它是否包含某些单词，例如加法或减法，然后查找整数。但是，在我当前的代码中，我运行它并收到以下错误消息：

Traceback (most recent call last):
    File "python", line 1, in <module>
    File "python", line 7, in calculator
IndexError: string index out of range

代码在下面输入。

def calculator(string):
    if "add" in string or "Add" in string:
        total = 0
        for i in range(len(string)): #loop for length of string
            try:
                if type(int(string[i])) == int: #checks to see if there is a number in the string
                    try:
                        if type(int(string[i+1])): #checks to see if the number is 2 digits
                            number_1 = int(string[i])*10 
                    except ValueError:
                        number_1 = int(string[i])
                total = total + number_1 #adds all the numbers to a total variable
            except ValueError:
                pass
        print (total)

如果有人可以帮助我，那就太好了！非常感谢！

Answer 1

我相信您的问题出在type(int(string[i+1]))

因为你有一个for 循环，i 已经可以指向string 的最后一个索引。当你添加1 时，你会得到一个IndexError

例子：

s = 'blabla'
for i in range(len(s)):
    print(s[i])

输出：

b
l
a
b
l
a

例子：

s = 'blabla'
for i in range(len(s)):
    print(s[i+1])

输出：

l
a
b
l
a

File "C:\Users\python\scratch\untitled-1.py", line 3, in <module>
  print(s[i+1])

builtins.IndexError: string index out of range

Answer 2

和我的朋友（@Kay Ace Elits）坐下来，发现有很多事情不对劲，但我们拼凑了起来

def calculator(string):
    if "add" in string:

        total = 0
        first_string = "" # before a in add
        second_string = "" # after d in add

        value_list = string.split('add')
        for number in value_list:
            total += int(number)

        print(total)

    elif  "Add" in string:
        total = 0
        first_string = ""
        second_string = ""

        value_list = string.split('Add')
        for number in value_list:
            total += int(number)

        print(total)

### our test your can modify for other factors
### like spellings and different operations
string = "22add43"
calculator(string)