sz is an invalid choice even though snappy is installed

[bitmask777]

pip freeze shows:
snappy==2.6
snappy-manifolds==1.0

but with whisper-backup -a=sz backup disk I get:
whisper-backup: error: option -a: invalid choice: '=sz' (choose from 'gz')

Any ideas?

[bitmask777]

Got it working. First, made a lame syntax mistake using = with the -a switch. Second, had to install the snappy C lib and then install python-snappy.