python - 使用 XPath 提取序列子集

Question

我正在寻找一个 XPATH 来将“集合”提取为单独的序列。它必须由 python lxml(它是 libxml2 的包装器)解释。

例如，给定以下内容:

<root>
    <sub1>
        <sub2>
            <Container>
                <item>1 - My laptop has exploded again</item>
                <item>2 - This is an issue which needs to be fixed.</item>
            </Container>
        </sub2>
        <sub2>
            <Container>
                <item>3 - It's still not working</item>
                <item>4 - do we have a working IT department or what?</item>
            </Container>
        </sub2>
        <sub2>
            <Container>
                <item>5 - Never mind - I got my 8 year old niece to fix it</item>
            </Container>
        </sub2>
    </sub1>
</root>

我希望能够“隔离”每个组或序列，例如序列 1 是:

1 - My laptop has exploded again
2 - This is an issue which needs to be fixed.

第二个序列:

3 - It's still not working
4 - do we have a working IT department or what?

第三个序列:

5 - Never mind - I got my 8 year old niece to fix it

“序列”所在的位置，用伪代码/python 翻译:

seq1 = ['1 - My laptop has exploded again', '2 - This is an issue which needs to be fixed.']
seq2 = ['3 - It's still not working', '4 - do we have a working IT department or what?']
seq 3 = ['5 - Never mind - I got my 8 year old niece to fix it']

从一些初步研究看来，sequences can't be nested但我想知道 these operators 是否有一些黑魔法可以实现。

Answer 1

1. 计算此 XPath 表达式:

   count(/*/*/*)

这会找到 <sub2> 的数量元素(等效且更具可读性，但更长，是:

count(/*/sub1/sub2))

对于每个 $n 1 至 count(/*/*/*)计算以下 XPath 表达式:

/*/*/*[$n]/*/item/text()

同样，这相当于更长且更具可读性:

/*/sub1/sub2[$n]/Container/item/text()

在评估上述表达式之前，请替换 $n实际值为$n (例如，对字符串使用 format() 方法。

对于提供的XML文档$n是 3，因此计算的实际 XPath 表达式是:

/*/*/*[1]/*/item/text()

，

/*/*/*[2]/*/item/text()

，

/*/*/*[3]/*/item/text()

它们各自产生以下结果:

集合(与语言相关——数组、序列、集合、 IEnumerable<string> 等):

"1 - My laptop has exploded again", "2 - This is an issue which needs to be fixed."

，

"3 - It's still not working", "4 - do we have a working IT department or what?"

，

"5 - Never mind - I got my 8 year old niece to fix it"