在字符串中查找数字，加 1 并替换

Question

我需要编写一个代码，其中一个字符串包含一个数字，然后这个数字递增 1，然后在初始字符串输入中打印出来。

它应该像这样工作

>>>addNumber('I slept 3 hours')
what number would you like to increment? 3
I slept 4 hours
>>>addNumber('I have 366 friends on facebook')
what number would you like to increment? 6
I have 377 friends on facebook

到目前为止我有这个，但我知道这是错误的，老实说我不知道该怎么做。

def incrementNumbers(statement):
    number1=(int(input('What number would you like to increment?')))
    number2 = number1 +1
    i=[]
    for numbers in statement:
        if numbers.isdigit():
            i.append(numbers)
            statement.replace(numbers,number2)

Answer 1

你可以在这里使用re.sub

>>> import re
>>> s = 'I have 366 friends on facebook'
>>> def addone(obj):
...     val = int(obj.group(1))
...     return str(val+1)
... 
>>> i = raw_input('what number would you like to increment?')
what number would you like to increment?6
>>> re.sub('({})'.format(i),addone,s)
'I have 377 friends on facebook'

另一个例子

>>> s = 'I slept 3 hours'
>>> i = raw_input('what number would you like to increment?')
what number would you like to increment?3
>>> re.sub('({})'.format(i),addone,s)
'I slept 4 hours'

你可以像这样定义你的函数

def addNumber(s):
    def addone(obj):
        val = int(obj.group(1))
        return str(val+1)

    i = raw_input('what number would you like to increment?')
    return(re.sub('({})'.format(i),addone,s))

但是我建议你有一个验证函数

i = raw_input('what number would you like to increment?')
if 0<int(i)<9:
    return(re.sub('({})'.format(i),addone,s))
else:
    return "Number out of range"

这将防止用户输入超出范围的值

Answer 2

根据您要求数值必须在0到8之间，您可以使用string.replace

def increment(s, inc):
    return s.replace(str(inc), str(inc + 1))

>>> s = 'I have 366 friends on facebook'
>>> inc = 6
>>> increment(s, 6)
'I have 377 friends on facebook'

Answer 3

您的代码中可能存在的错误是：

您正在尝试用 int 直接替换 string 中的类型数据。
也只检查 numbers.isdigit() 将修改所有数字，而不管您指定要修改的内容。

可能会更正您的代码以使其运行正确：

def incrementNumbers(statement):
    number1 = int(input('What number would you like to increment?'))
    number2 = number1 +1
    i=[]
    for numbers in statement:
        if numbers.isdigit() and int(numbers) == number1:
            i.append(numbers)
            statement.replace(numbers,str(number2))

您还可以将 incrementNumbers(statement) 函数更改为：

def incrementNumbers(statement):
    number1 = input('What number would you like to increment?')
    number2 = str(int(number1)+1)
    statement = statement.replace(number1,number2)
    return statement

我认为这比使用 for 循环更好。

在字符串中查找数字，加 1 并替换

find number in string, add 1 and replace

python

string

digit