需求：
        数据集的数据增强中，有时需要将xml标注文件中的类别做修改为新类别，或者将几个类别合并为一个类别。
 
解决方法：
        使用python+import xml.etree.ElementTree将xml标注文件中的类别名称做修改。代码如下：

python">import os
import glob
import xml.etree.ElementTree as et

def change_labels(source_dir):
    file_list = glob.glob(os.path.join(source_dir,"*.xml"))
    print(len(file_list))
    index = 1
    for file in file_list:
        print(file,index)
        index += 1
        tree_ = et.ElementTree()
        tree_.parse(file)

        root = et.Element("annotation")
        folder = et.SubElement(root, "folder")
        folder.text = "images"
        filename = et.SubElement(root, "filename")
        filename.text = tree_.find(".//filename").text
        path = et.SubElement(root, "path")
        path.text = "/home/Desktop/labels"
        source = et.SubElement(root, "source")
        database = et.SubElement(source, "database")
        database.text = "Unknown"
        size = et.SubElement(root, "size")
        width = et.SubElement(size, "width")
        width.text = tree_.find(".//width").text
        height = et.SubElement(size, "height")
        height.text = tree_.find(".//height").text
        depth = et.SubElement(size, "depth")
        depth.text = "3"
        segmented = et.SubElement(root, "segmented")
        segmented.text = "0"

        objects = tree_.findall(".//object")
        anchor = 0
        for object in objects:

            try:
                name_ = object.find("name").text
            except:
                print(file)
                print("-----------------------------------------")
                continue
            
            n = ""
            if name_ == "van" or name_ == "bus" or name_ == "truck":
                n = "car"
            else:
                n = name_
            object_ = et.SubElement(root, "object")
            name = et.SubElement(object_, "name")
            name.text = n
            pose = et.SubElement(object_, "pose")
            pose.text = "Unspecified"
            truncated = et.SubElement(object_, "truncated")
            truncated.text = "0"
            difficult = et.SubElement(object_, "difficult")
            difficult.text = "0"
            bndbox = et.SubElement(object_, "bndbox")
            xmin = et.SubElement(bndbox, "xmin")
            xmin.text = object.find(".//xmin").text
            ymin = et.SubElement(bndbox, "ymin")
            ymin.text = object.find(".//ymin").text
            xmax = et.SubElement(bndbox, "xmax")
            xmax.text = object.find(".//xmax").text
            ymax = et.SubElement(bndbox, "ymax")
            ymax.text = object.find(".//ymax").text

        tree = et.ElementTree(root)
        tree.write(file,encoding="utf-8")

if __name__ == '__main__':
    source_dir = "/home/Desktop/labels/Annotations"
    flip_images(source_dir)

 使用以上代码需要修改原图像和标注文件所在文件夹路径（source_dir），也需要修改类别，上述代码将"van”、“bus”、“truck”修改为“car”，这里可根据实际情况自行修改。亲测可用。