from mako.template import Template
from mako.lookup import TemplateLookup

lookup = TemplateLookup()
lookup.put_string("base.html", '-${self.body()}-')

t = Template('<%page args="x=None"/>${x}')
t_inherits = Template('<%inherit file="base.html"/><%page args="x=None"/>${x}', lookup=lookup)


print(t.render(x=9), t_inherits.render(x=9))
#9 -None-

#I want <%page/> to set the default value of a variable,
#but if I also inherit another template I can't overwrite that variable anymore.