def get_params(section_div, params_class):
    """Parse and return the parameters or returns of the documentation topic.

    Parameters
    ----------
    section_div : bs4.BeautifulSoup
        The BeautifulSoup object corresponding to the div with the "class"
        attribute equal to "section" in the html doc file.

    params_class: Str
        The value of the "class" attribute of the table row within
        `section_div` that contains the parameters or the returns.
        "field-odd field" for parameters. "field-even field" for returns.

    Returns
    -------
    Str:
        The parameters or returns of the topic.
    """

    parameters = []
    params_row = section_div.find("tr", attrs={"class": params_class})
    if not params_row:
        return
    params_cells = params_row.find("td", {"class": "field-body"})
    if not params_cells:
        return
    for tag in params_cells.children:
        try:
            t = tag.text
            t.strip()
            if t.startswith("\n"):
                t = t.lstrip()
                # The DDG system doesn't like "\\t" in abstract so using 4
                # spaces instead of "\t".
                # noqa See https://github.com/duckduckgo/zeroclickinfo-fathead/pull/584#discussion_r90515652
                t = " "*4 + t
            t = t.replace("\n", " ")
            t.rstrip()
            t = t + "\n"
            parameters.append(t)
        except AttributeError:
            pass

    return ''.join(parameters).rstrip()