Caching unicode characters with Memcached no longer works

[Chris Targett <chris@…>]

Since updating to Django 1.2.0 I am no longer able to cache unicode characters using the Memcached backend.

>>> from django import VERSION
>>> VERSION
(1, 1, 1, 'final', 0)
>>> import memcache
>>> memcache.__version__
'1.31'
>>>
>>> from django.core.cache import cache
>>> cache.set('test_key', u'\u2026')
>>> cache.get('test_key')
u'\u2026'
>>>




>>> from django import VERSION
>>> VERSION
(1, 2, 0, 'final', 0)
>>> import memcache
>>> memcache.__version__
'1.31'
>>>
>>> from django.core.cache import cache
>>> cache.set('test_key', u'\u2026')
Traceback (most recent call last):
  File "<console>", line 1, in ?
  File "/export/www/wwwroot/staging/django/staging6/code/valiant/core/cache/backends/prefix_wrapper.py", line 39, in set
    return self.backend.set(key, value, timeout)
  File "/export/www/wwwroot/staging/django/staging6/code/django/core/cache/backends/memcached.py", line 54, in set
    self._cache.set(smart_str(key), value, self._get_memcache_timeout(timeout))
  File "/usr/lib/python2.4/site-packages/memcache.py", line 293, in set
    return self._set("set", key, val, time)
  File "/usr/lib/python2.4/site-packages/memcache.py", line 317, in _set
    server.send_cmd(fullcmd)
  File "/usr/lib/python2.4/site-packages/memcache.py", line 507, in send_cmd
    self.socket.sendall(cmd + '\r\n')
  File "<string>", line 1, in sendall
UnicodeEncodeError: 'ascii' codec can't encode character u'\u2026' in position 40: ordinal not in range(128)
>>>

After reverting the changes here ​http://code.djangoproject.com/changeset/12637/django/trunk/django/core/cache/backends/memcached.py things seem to work again.

[Sasha Romijn]

Testing with django trunk, but a more recent version of the memcached module, it works:

>>> from django import VERSION
>>> VERSION
(1, 2, 1, 'alpha', 0)

>>> import memcache
>>> memcache.__version__
'1.45'

>>> from django.core.cache import cache
>>> cache.set('test_key', u'\u2026')
>>> cache.get('test_key')
u'\u2026'

So I guess your memcached module is too old, or this was fixed after 1.2 release.
Closing as worksforme.

[Karen Tracey]

This may be a problem specific to using the old (now deprecated and unmaintained) cmemcache bindings. If you are using those old bindings you should switch to python-memcached, see: ​http://docs.djangoproject.com/en/dev/topics/cache/#memcached.