Python

Question

我正在使用 Python (minidom) 解析 XML 文件并像 csv 文件一样打印输出：

0.0,0.0,51.3,46.6,
49.9,49.0,51.0,46.6,
36.0,24.0,47.8,42.2,
51.0,46.6,49.3,34.1,

相反，程序生成以下内容，跳过 'Q' 标签，除非它们是各自 'Event' 标签中的最后一个标签...为什么我的程序无法打印这些？

0.0,0.0,,46.6
49.9,49.0,,
36.0,24.0,42.2,
51.0,46.6,,

这是 XML 源文件：

<?xml version="1.0" encoding="UTF-8"?>
<Games id = "1">
  <Game id="1" competition_id="1">
    <Event id="0" x="0.0" y="0.0">
      <Q id="a" end_x="51.3" />
      <Q id="b" end_y="46.6" />
    </Event>
    <Event id="1" x="49.9" y="49.0">
      <Q id="a" end_x="51.0" />
      <Q id="b" end_y="46.6" />
      <Q id="c" q1="tap" />
    </Event>
    <Event id="2" x="0.0" y="0.0">
      <Q id="a" end_y="47.8" />
      <Q id="b" end_x="42.2" />
    </Event>
    <Event id="3" x="51.0" y="46.6">
      <Q id="a" end_y="49.3" />
      <Q id="b" end_x="34.1" />
      <Q id="c" q1="17.8" />
    </Event>
</Game>

这是我的代码：

from xml.dom.minidom import parse
import xml.dom.minidom

DOMTree = parse('myfile.xml');
collection = DOMTree.documentElement;

# Get all events in the collection
events = collection.getElementsByTagName("Event")

# Iterate through events
for event in events:
    start_x = event.getAttribute('x');
    start_y = event.getAttribute('y');

    qualifiers = event.getElementsByTagName('Q');

    # Iterate through qualifiers

    for qualifier in qualifiers:
        end_x= qualifier.getAttribute('end_x');
        end_y= qualifier.getAttribute('end_y');

    print start_x + ',' + start_y + ',' + end_x + ',' + end_y

Answer 1

如果您在限定符循环中查看 for 限定符的结构，循环内的 end_x 和 end_y 没有任何变化。这意味着代码运行并重新分配 end_x 和 end_y 的值。在循环结束时，end_x 和 end_y 是最后一个限定符

的值

from xml.dom.minidom import parse
import xml.dom.minidom

DOMTree = parse('myfile.xml');
collection = DOMTree.documentElement;

# Get all events in the collection
events = collection.getElementsByTagName("Event")

# Iterate through events
for event in events:
    start_x = event.getAttribute('x');
    start_y = event.getAttribute('y');

    qualifiers = event.getElementsByTagName('Q');

    # Iterate through qualifiers

    for qualifier in qualifiers:
        if(qualifier.hasAttribute('end_x')):
            end_x= qualifier.getAttribute('end_x');
        elif(qualifier.hasAttribute('end_y')):
            end_y= qualifier.getAttribute('end_y');

    print start_x + ',' + start_y + ',' + end_x + ',' + end_y

上面的代码应该可以满足您的需求。我注意到，最初的顺序是 end_x，然后是 end_y，然后顺序更改为 end_y end_x，因此在样本正确格式中，结束坐标被翻转。所以输出是

0.0,0.0,51.3,46.6,
49.9,49.0,51.0,46.6,
36.0,24.0,42.2,47.8,
51.0,46.6,34.1,49.3,

希望对您有所帮助

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