def convert_from_xml(cls, str_value):
if str_value not in ('1', '0', 'true', 'false'):
raise InvalidXmlError(
"value must be one of '1', '0', 'true' or 'false', got '%s'"
% str_value
)
return str_value in ('1', 'true')
def is_empty(self):
"""True if only a single empty `a:p` element is present."""
ps = self.p_lst
if len(ps) > 1:
return False
if not ps:
raise InvalidXmlError("p:txBody must have at least one a:p")
if ps[0].text != "":
return False
return True