如何获取XML文件文本中单词的排名？求解Vdepth排名提取失败问题

Hey there! Let's break down why your current XPath isn't working and how to get that rank value you need.

The Core Problem #

Your XML's mnemonicList contains a single text node with the comma-separated string: Mdepth,Vdepth,Bit Dist,TQ on btm. When you use //logData/mnemonicList/text(), you're grabbing that one entire string—not four separate nodes. That's why (//logData/mnemonicList/text())[2] throws "NO MATCH!"—there's no second text node to select.

Solutions Based on Your XPath Version #

If You're Using XPath 2.0+ (Most Modern Tools Support This)

This is the cleanest approach. Use the tokenize() function to split the string into a sequence of values, then either grab the second element directly or get its index (your desired rank value):

• To get the "Vdepth" string itself:

  tokenize(//logData/mnemonicList/text(), ',')[2]
  

• To get its rank (the number 2):

  index-of(tokenize(//logData/mnemonicList/text(), ','), 'Vdepth')
  

The index-of() function will return the position of "Vdepth" in the split list, which is exactly the rank you need.

If You're Stuck With XPath 1.0 (No Built-in Split Function)

We have to get creative with string manipulation. To calculate the rank of "Vdepth", count how many commas appear before it, then add 1:

string-length(substring-before(//logData/mnemonicList/text(), 'Vdepth')) - string-length(translate(substring-before(//logData/mnemonicList/text(), 'Vdepth'), ',', '')) + 1

Here's how this works:

1. substring-before(..., 'Vdepth') grabs everything before "Vdepth" (Mdepth,)
2. translate(..., ',', '') removes all commas from that substring, leaving Mdepth
3. Subtract the length of the comma-free string from the original substring length to get the number of commas (1)
4. Add 1 to get the rank (2)

Quick Verification #

If you just want to confirm "Vdepth" is in the second position, you can use this check:

starts-with(substring-after(//logData/mnemonicList/text(), ','), 'Vdepth')

It will return true if "Vdepth" follows the first comma.

内容的提问来源于stack exchange，提问作者Jun