通过遍历列表使用python创建XML文件

Question

我正在尝试获取一个类似于此的xml文件，以便将其导入moodle成绩册：

<results>
  <result>
    <student>1</student>
    <assignment>100</assignment>
    <score>0</score>
  </result>
  <result>
    <student>1</student>
    <assignment>101</assignment>
    <score>4</score>
  </result>
  <result>
    <student>1</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>100</assignment>
    <score>0</score>
  </result>
  <result>
    <student>2</student>
    <assignment>101</assignment>
    <score>4</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
</results>

我试图用python编写一些代码，在仔细阅读了文档之后，我能想到的最好的方法是：

import xml.etree.cElementTree as ET

students = [1,2]
assignments=[100,101,102]
scores=[0,4,10]
results = ET.Element("results")
result = ET.SubElement(results,"result")
student = ET.SubElement(result,"student")
assignment = ET.SubElement(result,"assignment")
score = ET.SubElement(result,"score")

for s in students:    
    for a in range(len(assignments)):
        student.text = str(s)
        assignment.text = str(assignments[a])
        score.text = str(scores[a])
        results.append(result)
tree = ET.ElementTree(results)
tree.write('test.xml')

这几乎满足了我的要求，但最后一个条目似乎覆盖了前面的所有条目，如图所示：

<results>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
  <result>
    <student>2</student>
    <assignment>102</assignment>
    <score>10</score>
  </result>
</results>

我试图找到一个解决方案，但似乎大多数问题只涉及编写一个带有不同元素的xml文件。我想不通的是如何使用同一个元素标记，但是为每个元素分配不同的值。

Answer 1

你需要移动这些线

result = ET.SubElement(results,"result")
student = ET.SubElement(result,"student")
assignment = ET.SubElement(result,"assignment")
score = ET.SubElement(result,"score")

进入for循环。否则你只是一遍又一遍地添加相同的result。

Answer 2

你需要做两件事：

• 将建议的行Eli移到for循环中。
• 从for循环中删除行：results.append(result)。SubElement工厂将父元素作为其第一个参数 （如您所知）它将新创建的实例附加到 起源。所以你不需要再附加它（你不会得到 任何错误，但是你会得到一组不同的结果 您指定的）。

然后循环应该如下所示：

for s in students:    
    for a in range(len(assignments)):

        result = ET.SubElement(results,"result")
        student = ET.SubElement(result,"student")
        assignment = ET.SubElement(result,"assignment")
        score = ET.SubElement(result,"score")

        student.text = str(s)
        assignment.text = str(assignments[a])
        score.text = str(scores[a])