c# - How do I know the node position under parent with selenium? -

i trying figure out how know position of current node under parent, using selenium , of time use xpath. because want extract columns of table in example number of columns dynamically generated

<tabe>     <tr>         <td>23</td>         <td>42</td>         <td>31</td>     </tr>     <tr>         <td>13</td>         <td>21</td>         <td>32</td>     </tr> </table> 

so lets need second colunm (42 , 21), since the content dynamically generated don't know if second colum know want colum number 42. selenium 42 easily. bu need position of td.

i have thought in algorithm might complex , slow. like:

1. get html code under current
2. get parent of current node
3. iterate (while counting) got parent , compare each child inner code 1 found.
4. some other validations need think
5. when found that's colum

that algorithm have issues "what if there 2 elements same inner code" , mentioned might slow , don't let me start when start considering row , colum span (currently need position in current row).

so there easier way this? selenium function don't know or maybe way though xpath?

thanks :)

playing around little xpath came following query;

//tr[2]/td[position()=count(//tr[1]/td[.='42']/preceding-sibling::*) + 1] 

this give relative positioned "td" of 2nd "tr" selection of text found in "td" of 1st "tr".

this based on find position of node using xpath