def remove_html(s):
    """
    Removes all HTML tags from a string.
    """
    tmp = s
    #while (sub := tmp.find('<')) >= 0:
    sub = tmp.find('<')
    while sub >= 0:
        tmp1 = tmp[:sub]
        tmp2 = tmp[sub:]

        sub = tmp2.find('>')
        tmp = tmp1 + tmp2[sub+1:]

        sub = tmp.find('<')

    return tmp