              cnt = k[1]
              maxcnts[msgid] = max(cnt, maxcnts.get(msgid, 0))
              pdict.setdefault(msgid, {})[cnt] = v
          else:
              raise TypeError(k)
      for k, v in pdict.items():
          catalog[k] = [v.get(i, '') for i in range(maxcnts[msgid] + 1)]
  
      return catalog, plural
  
 
</s> remove             pdict.setdefault(msgid, {})[cnt] = v
 </s> add             pdict.setdefault(msgid, {})[cnt] = value </s> remove         if isinstance(k, six.string_types):
            catalog[k] = v
        elif isinstance(k, tuple):
            msgid = k[0]
            cnt = k[1]
 </s> add         if isinstance(key, six.string_types):
            catalog[key] = value
        elif isinstance(key, tuple):
            msgid = key[0]
            cnt = key[1] </s> remove     for k, v in t.items():
        if k == '':
 </s> add     trans_fallback_cat = trans._fallback._catalog if trans._fallback else {}
    for key, value in itertools.chain(six.iteritems(trans_cat), six.iteritems(trans_fallback_cat)):
        if key == '' or key in catalog: </s> remove     if '' in t:
        for l in t[''].split('\n'):
            if l.startswith('Plural-Forms:'):
                plural = l.split(':', 1)[1].strip()
 </s> add     if '' in trans_cat:
        for line in trans_cat[''].split('\n'):
            if line.startswith('Plural-Forms:'):
                plural = line.split(':', 1)[1].strip() </s> remove     default_locale = to_locale(settings.LANGUAGE_CODE)
 </s> add 
            raise TypeError(key)
              cnt = k[1]
              maxcnts[msgid] = max(cnt, maxcnts.get(msgid, 0))
              pdict.setdefault(msgid, {})[cnt] = v
          else:
            raise TypeError(key)
      for k, v in pdict.items():
          catalog[k] = [v.get(i, '') for i in range(maxcnts[msgid] + 1)]
  
      return catalog, plural
  
keep keep keep keep replace keep keep keep keep keep
 Reused the DjangoTranslation class for the javascript_catalog view

Thanks Tim Graham and Cristiano Coelho for the reviews.
Refs #26328, #26319. 
django/views/i18n.py