how can I combine 2 dataset with different/same features?
Good to hear.
Currently I did not use map , just fetch src and tgt from the 2 dataset and merge them.
It will be a release if you can deal with it at the backend.
Thanks.
to combine 2 dataset by one-one map like ds = zip(ds1, ds2):
ds1: {'text'}, ds2: {'text'}, combine ds:{'src', 'tgt'} 
or different feature:
ds1: {'src'}, ds2: {'tgt'}, combine ds:{'src', 'tgt'}
how can I combine 2 dataset with different/same features? 
 to combine 2 dataset by one-one map like ds = zip(ds1, ds2):
ds1: {'text'}, ds2: {'text'}, combine ds:{'src', 'tgt'} 
or different feature:
ds1: {'src'}, ds2: {'tgt'}, combine ds:{'src', 'tgt'} 
 Good to hear.
Currently I did not use map , just fetch src and tgt from the 2 dataset and merge them.
It will be a release if you can deal with it at the backend.
Thanks.