• remove：删除结点
• append：添加节点

import xml.etree.ElementTree as ET


# 删除某一固定类别的结点
def removecls(xml_path, cls):
    tree = ET.parse(xml_path)  # 保存xml文件是tree
    root = tree.getroot()  # 修改xml问价是对root操作

    # 通常用find来获得某一结点的地址，然后再继续访问一些元素值
    # 通过findall或者iterfind，都可以直接获取到所有object的结点地址
    objects = root.findall('object')
    for obj in objects:
        cls = obj.find('name').text
        if cls == 'loc':
            root.remove(obj)

    tree.write('caogao.xml')    # 保存xml


# 加入一个object节点
def appendobj(xml_path, name, xmin, ymin, xmax, ymax):
    tree = ET.parse(xml_path)
    root = tree.getroot()

    new_obj = ET.Element('object')
    new_obj.tail = '\n'
    root.append(new_obj)

    new_obj_name = ET.Element('name')
    new_obj_name.text = name
    new_obj.append(new_obj_name)

    new_obj_box = ET.Element('bndbox')
    new_obj.append(new_obj_box)

    new_obj_box_xmin = ET.Element('xmin')
    new_obj_box_xmin.text = str(xmin)
    new_obj_box.append(new_obj_box_xmin)

    new_obj_box_ymin = ET.Element('ymin')
    new_obj_box_ymin.text = str(ymin)
    new_obj_box.append(new_obj_box_ymin)

    new_obj_box_xmax = ET.Element('xmax')
    new_obj_box_xmax.text = str(xmax)
    new_obj_box.append(new_obj_box_xmax)

    new_obj_box_ymax = ET.Element('ymax')
    new_obj_box_ymax.text = str(ymax)
    new_obj_box.append(new_obj_box_ymax)

    tree.write('caogao2.xml')   # 保存xml


if __name__ == '__main__':
    xml_path = r'G:\pycharmprojects\ScriptCodes_lwd\linepaste\lines\xmlloc\1a.xml'

    # 1.删除某一结点
    removecls(xml_path, '')

    # 2.添加一个结点
    # appendobj(xml_path, 'loc', 200, 300, 300, 400)