Максим

p_s = './static/csv_s/as_is/'
path_start = os.path.dirname(p_s)
p_f = './static/csv_s/to_be/'
path_finish = os.path.dirname(p_f)

cur_dir = os.path.dirname(os.path.abspath(__file__))
path_start = '{}/static/csv_s/as_is/'.format(cur_dir)
path_finish = '{}/static/csv_s/to_be/'.format(cur_dir)

1. Экспорт из исходного ИМа информации по товарам в файл
   
2. Импорт товаров в новый ИМ из файла
   

import ast

str_number = '58'
print(ast.literal_eval(str_number))
# output: 58 - <type 'int'>

str_dict = '{"name": "vasya", "age": 30}'
print(type(ast.literal_eval(str_dict)))
# output: {"name": "vasya", "age": 30} - <type 'dict'>

$arr = [
        'some' => '',
        'code' => [100, 200, 300]
    ];
$query = http_build_query($arr);

$flowers = array( 
                  array("розы", 100 , 15),
                  array("тюльпаны", 60 , 25),
                  array("орхидеи", 180 , 7) 
                );
$newArr = [];
foreach($flowers as $arFlower){
    [$flower, $price, $quantity] = $arFlower;
    $flowerItem['Название'] = $flower;
    $flowerItem['Цена'] = $price;
    $flowerItem['Количество'] = $quantity;
    $newArr[] = $flowerItem;
}

<?php
if ($_FILES['img']['tmp_name'][0]){
    // ....
}
?>