lazy student

import re

HOMEWORK = r'C:\Users\BenSalem\homework.txt'
SOLUTIONS = r'C:\Users\BenSalem\solutions.txt'

def add(str):
    result = 0
    for i in str:
            result = result + i
    return result

def substract(str):
    result = 0
    for i in str:
            result = result - i
    return result

def divide(str):
    result = 0
    for i in str:
            result = result / i
    return result

def multiply(str):
    result = 0
    for i in str:
            result = result * i
    return result

h_file = open(HOMEWORK,'r')
for line in h_file:
    int_list = map(int, re.findall(r'\d+', line))
    if(line[2]=='+'):
       add_result0 = add(int_list)
       data0 = line[:-1]
       send0 = '{} = {}'.format(data0, add_result0) + '\n'
       s_file = open(SOLUTIONS,'a')
       s_file.write(send0)
    elif(line[2]=='/'):
        devide_result = divide(int_list)
        data1 = line[:-1]
        send1 = '{} = {}'.format(data1,   devide_result) + '\n'
        s_file = open(SOLUTIONS, 'a')
        s_file.write(send1)
    elif(line[2]=='-'):
        substract_result = substract(int_list)
        data2 = line[:-1]
        send2 = '{} = {}'.format(data2, substract_result) + '\n'
        s_file = open(SOLUTIONS, 'a')
        s_file.write(send2)
    elif(line[2]=='*'):
        multiply_result = multiply(int_list)
        data3 = line[:-1]
        send3 = '{} = {}'.format(data3, multiply_result) + '\n'
        s_file = open(SOLUTIONS, 'a')
        s_file.write(send3)