          value = self._convert_to_charset(value, 'latin-1', mime_encode=True)
          self._headers[header.lower()] = (header, value)
  
      def __delitem__(self, header):
          with suppress(KeyError):
              del self._headers[header.lower()]
  
      def __getitem__(self, header):
          return self._headers[header.lower()][1]
  
 
</s> remove             with suppress(KeyError):
 </s> add             try: </s> remove 
        with suppress(KeyError):
 </s> add         except KeyError:
            pass
        try: </s> remove         with suppress(KeyError):
 </s> add         try:
        try:
          value = self._convert_to_charset(value, 'latin-1', mime_encode=True)
          self._headers[header.lower()] = (header, value)
  
      def __delitem__(self, header):
        try:
              del self._headers[header.lower()]
  
      def __getitem__(self, header):
          return self._headers[header.lower()][1]
  
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/http/response.py