Русские символы в xml

Пишу программу которая должна сохранять товары в формате xml. Но появилась проблема, русские буквы отображаются знаками вопроса

<listing lang="ru-RU">
    <title>text</title>
    <content>content</content>
    <category>cati</category>
    <categoryid>categoryid</categoryid>
    <contactname>contactname</contactname>
    <price>price</price>
    <currency>currency</currency>
    <city_area>city_area</city_area>
    <city>city</city>
    <region>region</region>
    <countryId>countryId</countryId>
    <country>country</country>
    <custom name="tip">tg</custom>
    <custom name="p1">�������</custom>
</listing>

Я думаю что дело в кодировке, как мне добавить кодировку в начале скрипта ?

Вот сам скрипт

from xml.dom import minidom

root = minidom.Document()

xml_root = root.createElement('listings')
root.appendChild(xml_root)
u = 0 
while u <10:
    categoriesChild = root.createElement('listing')
    categoriesChild.setAttribute('lang', f'ru-RU')
    xml_root.appendChild(categoriesChild)


    categoryChild = root.createElement('title')
    textName = root.createTextNode('text')
    categoryChild.appendChild(textName)

    contentChild = root.createElement('content')
    content = root.createTextNode('content')
    contentChild.appendChild(content)

    catChild = root.createElement('category')
    catText = root.createTextNode('cati')
    catChild.appendChild(catText)

    categoryidChild = root.createElement('categoryid')
    categoryidText = root.createTextNode('categoryid')
    categoryidChild.appendChild(categoryidText)

    contactnameChild = root.createElement('contactname')
    contactnameText = root.createTextNode('contactname')
    contactnameChild.appendChild(contactnameText)

    priceChild = root.createElement('price')
    priceText = root.createTextNode('price')
    priceChild.appendChild(priceText)

    currencyChild = root.createElement('currency')
    currencyText = root.createTextNode('currency')
    currencyChild.appendChild(currencyText)

    city_areaChild = root.createElement('city_area')
    city_areaText = root.createTextNode('city_area')
    city_areaChild.appendChild(city_areaText)

    cityChild = root.createElement('city')
    cityText = root.createTextNode('city')
    cityChild.appendChild(cityText)

    regionChild = root.createElement('region')
    regionText = root.createTextNode('region')
    regionChild.appendChild(regionText)

    countryIdChild = root.createElement('countryId')
    countryIdText = root.createTextNode('countryId')
    countryIdChild.appendChild(countryIdText)

    countryChild = root.createElement('country')
    countryText = root.createTextNode('country')
    countryChild.appendChild(countryText)

    tgChild = root.createElement('custom')
    tgChild.setAttribute('name', f'tip')
    tgText = root.createTextNode('tg')
    tgChild.appendChild(tgText)

    artChild = root.createElement('custom')
    artChild.setAttribute('name',f'p1')
    artText = root.createTextNode('Артикул')
    artChild.appendChild(artText)

    categoriesChild.appendChild(categoryChild)
    categoriesChild.appendChild(contentChild)
    categoriesChild.appendChild(catChild)
    categoriesChild.appendChild(categoryidChild)
    categoriesChild.appendChild(contactnameChild)
    categoriesChild.appendChild(priceChild)
    categoriesChild.appendChild(currencyChild)
    categoriesChild.appendChild(city_areaChild)
    categoriesChild.appendChild(cityChild)
    categoriesChild.appendChild(regionChild)
    categoriesChild.appendChild(countryIdChild)
    categoriesChild.appendChild(countryChild)
    categoriesChild.appendChild(tgChild)
    categoriesChild.appendChild(artChild)
    u += 1


xml_root.appendChild(categoriesChild)

xml_str = root.toprettyxml(indent="\t")
save_path_file = "yandex2.xml"

with open(save_path_file, "w") as f:
f.write(xml_str)