Question

What regex would match a nested table with identifiable text in the table cell? I’ve tried but failed to come up with a regular expression to extract the specific table I want with out grabbing the beginning and end of both tables in the example. Here is something to get started: “<table>.*?</table>“

<table>
    <tr>
        <td>
            <table>
                <tr><td>Code1</td></tr>
                <tr><td>some data</td></tr>
                <tr><td>etc ...</td></tr>
            </table>
        </td>
    </tr>
    <tr>
        <td>
            <table>
                <tr><td>Code2</td></tr>
                <tr><td>some data</td></tr>
                <tr><td>etc ...</td></tr>
            </table>
        </td>
    </tr>
</table>

Say I want to extract the table containing “Code2”. What regex will match specifically and only that table?

Answer 1

The following regex will find your table:

(?ms)<table>((?!<table>).)*<td>Code2</td>.*?</table>

With (?ms) you turn on “multiline matches” (m) and “dot matches newlines, too” (s). Then you have a negative lookahead (?!) to make sure you have no second start of a table inside your match.