complete function list2table take the parameter s which is a string of HTML as input and return a string. list2table extracts the data from all ordered lists in s and converts each of them to a table.

Here is an implementation of the function:

import re

def list2table(s):
    # Find all ordered lists in the input string
    ol_regex = re.compile(r'<ol>(.*?)</ol>', re.DOTALL)
    ol_matches = ol_regex.findall(s)

    # Process each ordered list and convert it to a table
    for ol_match in ol_matches:
        # Find all list items in the ordered list
        li_regex = re.compile(r'<li>(.*?)</li>', re.DOTALL)
        li_matches = li_regex.findall(ol_match)

        # Create the table header row
        header_row = '<tr>'
        for li_match in li_matches:
            header_row += f'<th>{li_match}</th>'
        header_row += '</tr>'

        # Create the table data rows
        data_rows = ''
        for i in range(len(li_matches)):
            data_row = '<tr>'
            for li_match in li_matches:
                # Find the ith item in the current list item
                item_regex = re.compile(r'<li>(.*?)</li>', re.DOTALL)
                item_match = item_regex.findall(li_match)[i]
                data_row += f'<td>{item_match}</td>'
            data_row += '</tr>'
            data_rows += data_row

        # Replace the ordered list with the table
        table = f'<table>{header_row}{data_rows}</table>'
        s = s.replace(ol_match, table)

    return s

The `list2table` function uses regular expressions to extract the data from all ordered lists in the input string. It then creates a table for each ordered list by creating a header row from the list items and a data row for each item in each list item. Finally, it replaces each ordered list with its corresponding table in the output string.