-replace switch'case by indexing

- Add test case
- Add constructors
- Add getItem string

- Fix bugs
- Add more tests

- Tensor iterator
- asNumpy
- TextFileDataset

- Tensor(Numpy)

- Super > 2D
- Add more test cases for GeneratorDataset

- Change StartAddr to GetBuffer and GetMutableNuffer

- Raise an error if batch is used with strings

Clean-up work

Merge pull request !1157 from ms_yan/concat_dataset

Merge pull request !1126 from xiefangqi/voc_support_detection

change to use __add__ operation instead ds.concat

Merge pull request !508 from EricZ/master

Merge pull request !511 from AdelShafiei/uniform_augmentation

Initial commit for dataset op python

Added signature to barrier

Adde compiling barrier code

Rebasing, fixed new compile errors

Final fix for make_unique

Added pybind API for barrier

Fixed pyfunc invocation

python interface - sync_wait

!1 sync_wait python interface
* python interface - sync_wait

fix test

update test

update test

Added new test case

add test case

test for shuffle + batch

Added two-sync test case

Restrited that no shuffle after sync

Added sync to pipeline info

block first databuffer as well

Intelligently get batch size

Fix default case

Lock Pair shares among all iterators

Added fix for empty character

Fixed up test case formatting

Fix end of epoch in sync_wait

Fixing CI

Merge pull request !404 from JunhanHu/python_sampler_for_cpp_dataset

Merge pull request !378 from h.farahat/multi_itr

-- Iterator list is keeping  all created iterators wihtout cleaning them up
-- alter tree modifies the original.

Merge pull request !183 from JunhanHu/cpp_sampler

Merge pull request !273 from liyong126/mindrecord_subset_sampler_python

adjust internal api

fix clang

pybind fix

Signed-off-by: leonwanghui <leon.wanghui@huawei.com>