RedisCache only accepts string keys

[mcdallas]

Currently RedisCache only accepts string keys due to the 'key_prefix' parameter that gets concatenated to each key. Even SimpleCache accepts integer keys and redis itself even accepts sets as keys.

I am using werkzeug 0.12.2 and Python 3.6.1

[davidism]

So what's your proposal? I don't want to drop the prefix, but converting arbitrary objects to string might not be correct.

[mcdallas]

Maybe add a check to see if the attempted key is a string and only then add the prefix.

[davidism]

How about if a prefix is defined, string keys are required, if it's none any key is allowed with the understanding that collisions are easier.

[mcdallas]

That works too. I can send a PR this weekend.

[davidism]

That would be really helpful, thanks!

[davidism]

The cache is deprecated, see #1249