          if not self.timezone:
              return ""
  
          name = None
          with suppress(Exception):
              # pytz raises AmbiguousTimeError during the autumn DST change.
              # This happens mainly when __init__ receives a naive datetime
              # and sets self.timezone = get_default_timezone().
              name = self.timezone.tzname(self.data)
          if name is None:
 
</s> remove             name = self.timezone.tzname(self.data)
 </s> add             pass </s> remove         with suppress(NotImplementedError):
 </s> add         try: </s> remove             with suppress(KeyError):
 </s> add             try: </s> remove     with suppress(KeyError):
 </s> add     try:
        try:
            name = self.timezone.tzname(self.data)
        except Exception:
          if not self.timezone:
              return ""
  
          name = None
        try:
            name = self.timezone.tzname(self.data)
        except Exception:
              # pytz raises AmbiguousTimeError during the autumn DST change.
              # This happens mainly when __init__ receives a naive datetime
              # and sets self.timezone = get_default_timezone().
              name = self.timezone.tzname(self.data)
          if name is None:
keep keep keep keep replace keep keep keep keep keep
 Reverted "Fixed #27818 -- Replaced try/except/pass with contextlib.suppress()."

This reverts commit 550cb3a365dee4edfdd1563224d5304de2a57fda
because try/except performs better. 
django/utils/dateformat.py