latex_elements = {
    'preamble': r'''
makeatletter
   fancypagestyle{normal}{
% this is the stuff in sphinx.sty
    fancyhf{}
    fancyfoot[LE,RO]{{py@HeaderFamilythepage}}
% we comment this out and
    %fancyfoot[LO]{{py@HeaderFamilynouppercase{rightmark}}}
    %fancyfoot[RE]{{py@HeaderFamilynouppercase{leftmark}}}
% add copyright stuff
    fancyfoot[LO,RE]{{This is textcopyright 2019, Sphinx Team.}}
% again original stuff
    fancyhead[LE,RO]{{py@HeaderFamily @titlesphinxheadercommapy@release}}
    renewcommand{headrulewidth}{0.4pt}
    renewcommand{footrulewidth}{0.4pt}
    }
% this is applied to each opening page of a chapter
   fancypagestyle{plain}{
    fancyhf{}
    fancyfoot[LE,RO]{{py@HeaderFamilythepage}}
    renewcommand{headrulewidth}{0pt}
    renewcommand{footrulewidth}{0.4pt}
% add copyright stuff for example at left of footer on odd pages,
% which is the case for chapter opening page by default
    fancyfoot[LO,RE]{{This is textcopyright 2019, Sphinx Team.}}
    }
makeatother
''',
}