Empty return from 'adata[adata.obs.leiden.eq("3")]'

[jingquanlim]

I am going through the tutorial on single-cell analysis. Have managed to reproduce much of the shown until this line

adata_bcells = adata[adata.obs.leiden.eq("3")]

This returned an empty object. I tried "adata.obs[adata.obs.leiden.eq("3")]" but the subsequent code doesn't work with this naive 'quick-fix' of mine.

Will be great if there are some read-in helper code for the .h5 from 10X's CellRanger or Singleron's CeleScope too. Thanks!