import re


def parse_full_section(section_name, docs):
    """
    Find warning defined in the documentation.

    Parameters
    ----------
    docs : str

    Returns
    -------
    str or None
        Returns warnings from documentation or ``None`` if
        function didn't find it.
    """
    parser = re.compile(r"{}\s+-+\s+(?P<section_text>(.*\n)+?)\s+"
                        # Here we try to find next section title or
                        # the end of the documentation
                        r"([\w\ ]+\n\s+-+\s+|$)"
                        r"".format(section_name))
    parsed_doc_parts = parser.findall(docs)

    if not parsed_doc_parts:
        return None

    section_text_block = parsed_doc_parts[0]
    full_section_text = section_text_block[0]

    # Regexp can catch multiple `\n` symbols at the and of
    # the section. For this reason we need to get rid of them.
    return full_section_text.rstrip()