问如何将数字减法字符串转换为Python中的整数？

EN

import ast

str_a = '10-5'
c = ast.literal_eval(str_a) + 3
print(c)
str_a = '10+5-2' # you can use any operation not just subtraction and you can add as many numbers as you want
c = ast.literal_eval(str_a) + 2
print(c)

8
15

import re

str_a = '10-5'
vals = map(int, re.split("\W+", str_a))
new_value = vals[0] - vals[-1] + 3

8

str_a = '10-5'
left, right = str_a.split('-')
b = 3
c = (int(left) - int(right)) + b

import ast
str_a = '10-5'
b = 3
c = ast.literal_eval(str_a) + b