如何计算XML文件中的数字(字符串格式)

import xml.etree.ElementTree as ET

def calculate_numbers_in_xml(xml_file):
    tree = ET.parse(xml_file)
    root = tree.getroot()

    numbers = []

    for element in root.iter():
        if element.text is not None:
            try:
                number = float(element.text)
                numbers.append(number)
            except ValueError:
                pass

        for key, value in element.items():
            try:
                number = float(value)
                numbers.append(number)
            except ValueError:
                pass

    sum_of_numbers = sum(numbers)
    average_of_numbers = sum_of_numbers / len(numbers)
    max_number = max(numbers)
    min_number = min(numbers)

    return {
        'sum': sum_of_numbers,
        'average': average_of_numbers,
        'max': max_number,
        'min': min_number
    }