版权声明：转载请说明来源，谢谢 https://blog.csdn.net/wsp_1138886114/article/details/86576900
xml 访问与查找
import xml.etree.ElementTree as ET
tree = ET.parse('students.xml')
root = tree.getroot() # 使用getroot()获取根节点，得到的是一个Element对象
#root = ET.fromstring(country_data_as_string) #从字符串变量中读取，返回的是Element对象
########################## 访问XML ###################################
"""
tag = element.text #访问Element标签
attrib = element.attrib #访问Element属性
text = element.text #访问Element文本
"""
for element in root.findall('student'):
tag = element.tag # 访问Element标签
attrib = element.attrib # 访问Element属性
text = element.find('name').text # 访问Element文本
print(tag, attrib, text)
print(root[0][0].text) # 子节点是嵌套的，我们可以通关索引访问特定的子节点
########################## 查找元素 ###################################
print("============ Element.iter() ===============")
for student in root.iter('student'): # Element.iter()
print(student[0].text)
print("============ Element.findall() ============")
for element in root.findall('student'):# Element.findall()
name = element.find('name').text
age = element.find('age').text
score = element.find('score').text
print (name,age,score)
students.xml文件内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<students>
<student>
<name>张三</name>
<age>18</age>
<score>89</score>
</student>
<student>
<name>李四</name>
<age>19</age>
<score>81</score>
</student>
<student>
<name>王五</name>
<age>17</age>
<score>92</score>
</student>
</students>
xml 创建与修改
import xml.etree.ElementTree as ET
########################## 创建xml文件 ################################
a = ET.Element("root") #创建根节点
b = ET.SubElement(a,"sub1") #创建子节点，并添加属性
b.attrib = {"name":"name attribute"}
c = ET.SubElement(a,"sub2") #创建子节点，并添加数据
c.text = "test"
tree = ET.ElementTree(a) #创建elementtree对象，写文件
tree.write("test.xml")
########################## 修改XML ###################################
"""
ElementTree.write() 将构建的XML文档写入文件。
Element.text = '' 直接改变字段内容
Element.append(Element) 为当前的Elment对象添加子对象
Element.remove(Element) 删除Element节点
Element.set(key, value) 添加和修改属性
ElementTree.write('filename.xml') 写出（更新）XMl文件
"""
updateTree = ET.parse("test.xml") # 读取待修改文件
root = updateTree.getroot()
newEle = ET.Element("NewElement") # 创建新节点并添加为root的子节点
newEle.attrib = {"name":"NewElement","age":"20"}
newEle.text = "This is a new element"
root.append(newEle) # 更新xml
sub1 = root.find("sub1") # 修改sub1的name属性
sub1.set("name","New Name")
sub2 = root.find("sub2") # 修改sub2的数据值
sub2.text = "New Value"
updateTree.write("test.xml") # 写回原文件
test.xml文件内容:
<root><sub1 name="name attribute" /><sub2>test</sub2></root>
更新后：
<root><sub1 name="New Name" /><sub2>New Value</sub2><NewElement age="20" name="NewElement">This is a new element</NewElement></root>
xml 增删改查 – 综合案例
from xml.etree.ElementTree import ElementTree,Element
def read_xml(in_path):
'''''读取并解析xml文件
in_path: xml路径
return: ElementTree'''
tree = ElementTree()
tree.parse(in_path)
return tree
def write_xml(tree, out_path):
'''''将xml文件写出
tree: xml树
out_path: 写出路径'''
tree.write(out_path, encoding="utf-8", xml_declaration=True)
def if_match(node, kv_map):
'''''判断某个节点是否包含所有传入参数属性
node: 节点
kv_map: 属性及属性值组成的map'''
for key in kv_map:
if node.get(key) != kv_map.get(key):
return False
return True
# ----------------search -----------------
def find_nodes(tree, path):
'''''查找某个路径匹配的所有节点
tree: xml树
path: 节点路径'''
return tree.findall(path)
def get_node_by_keyvalue(nodelist, kv_map):
'''''根据属性及属性值定位符合的节点，返回节点
nodelist: 节点列表
kv_map: 匹配属性及属性值map'''
result_nodes = []
for node in nodelist:
if if_match(node, kv_map):
result_nodes.append(node)
return result_nodes
# ---------------change ----------------------
def change_node_properties(nodelist, kv_map, is_delete=False):
'''修改/增加 /删除 节点的属性及属性值
nodelist: 节点列表
kv_map:属性及属性值map'''
for node in nodelist:
for key in kv_map:
if is_delete:
if key in node.attrib:
del node.attrib[key]
else:
node.set(key, kv_map.get(key))
def change_node_text(nodelist, text, is_add=False, is_delete=False):
'''''改变/增加/删除一个节点的文本
nodelist:节点列表
text : 更新后的文本'''
for node in nodelist:
if is_add:
node.text += text
elif is_delete:
node.text = ""
else:
node.text = text
def create_node(tag, property_map, content):
'''新造一个节点
tag:节点标签
property_map:属性及属性值map
content: 节点闭合标签里的文本内容
return 新节点'''
element = Element(tag, property_map)
element.text = content
return element
def add_child_node(nodelist, element):
'''''给一个节点添加子节点
nodelist: 节点列表
element: 子节点'''
for node in nodelist:
node.append(element)
def del_node_by_tagkeyvalue(nodelist, tag, kv_map):
'''''同过属性及属性值定位一个节点，并删除之
nodelist: 父节点列表
tag:子节点标签
kv_map: 属性及属性值列表'''
for parent_node in nodelist:
children = parent_node.getchildren()
for child in children:
if child.tag == tag and if_match(child, kv_map):
parent_node.remove(child)
if __name__ == "__main__":
################ 1. 读取xml文件 ##########
tree = read_xml("test_02.xml")
################ 2. 属性修改 ###############
nodes = find_nodes(tree, "processers/processer") # 找到父节点
result_nodes = get_node_by_keyvalue(nodes, {"name": "BProcesser"}) # 通过属性准确定位子节点
change_node_properties(result_nodes, {"age": "1"}) # 修改节点属性
change_node_properties(result_nodes, {"value": ""}, True) # 删除节点属性
################# 3. 节点修改 ##############
a = create_node("person", {"age": "15", "money": "200000"}, "this is the firest content") # 新建节点
add_child_node(result_nodes, a) # 插入到父节点之下
################# 4. 删除节点 ################
del_parent_nodes = find_nodes(tree, "processers/services/service") # 定位父节点
target_del_node = del_node_by_tagkeyvalue(del_parent_nodes, "chain", {"sequency": "chain1"}) # 准确定位子节点并删除之
################# 5. 修改节点文本 ############
text_nodes = get_node_by_keyvalue(find_nodes(tree, "processers/services/service/chain"), {"sequency": "chain3"}) # 定位节点
change_node_text(text_nodes, "new text")
################ 6. 输出到结果文件 ##########
write_xml(tree, "./xiugai.xml")
案例xml文件(修改前)
<?xml version="1.0" encoding="UTF-8"?>
<framework>
<processers>
<processer name="AProcesser" file="lib64/A.so"
path="/tmp">
</processer>
<processer name="BProcesser" file="lib64/B.so" value="fordelete">
</processer>
<processer name="BProcesser" file="lib64/B.so2222222"/>
<services>
<service name="search" prefix="/bin/search?"
output_formatter="OutPutFormatter:service_inc">
<chain sequency="chain1"/>
<chain sequency="chain2"></chain>
</service>
<service name="update" prefix="/bin/update?">
<chain sequency="chain3" value="fordelete"/>
</service>
</services>
</processers>
</framework>
案例xml文件(修改后)
<?xml version='1.0' encoding='utf-8'?>
<framework>
<processers>
<processer file="lib64/A.so" name="AProcesser" path="/tmp">
</processer>
<processer age="1" file="lib64/B.so" name="BProcesser">
<person age="15" money="200000">this is the firest content</person></processer>
<processer age="1" file="lib64/B.so2222222" name="BProcesser"><person age="15" money="200000">this is the firest content</person></processer>
<services>
<service name="search" output_formatter="OutPutFormatter:service_inc" prefix="/bin/search?">
<chain sequency="chain2" />
</service>
<service name="update" prefix="/bin/update?">
<chain sequency="chain3" value="fordelete">new text</chain>
</service>
</services>
</processers>
</framework>
鸣谢
http://www.runoob.com/python/python-xml.html
https://www.cnblogs.com/AlwinXu/p/5483177.html
特别鸣谢
https://blog.csdn.net/piaodexin/article/details/77371343