MindSpore text dataset API import error on Windows

[leonwanghui]

Environment

Hardware Environment(Ascend/GPU/CPU):

/device cpu

Software Environment:

• MindSpore version (source or binary): v1.1.1, v1.2.0-rc
• Python version (e.g., Python 3.7.5): Python 3.7.5
• OS platform and distribution (e.g., Linux Ubuntu 16.04): Windows 10
• GCC/Compiler version (if compiled from source): none

Describe the current behavior

When I tried to import PythonTokenizer from MindSpore text dataset API, some errors occurred:

>>> from mindspore.dataset import text
>>> text.__all__
['Lookup', 'JiebaTokenizer', 'UnicodeCharTokenizer', 'Ngram', 'to_str', 'to_bytes', 'Vocab', 'WordpieceTokenizer', 'TruncateSequencePair', 'ToNumber', 'PythonTokenizer', 'SlidingWindow', 'SentencePieceVocab', 'SentencePieceTokenizer', 'SPieceTokenizerOutType', 'SentencePieceModel', 'SPieceTokenizerLoadType']
>>> text.PythonTokenizer
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'mindspore.dataset.text' has no attribute 'PythonTokenizer'

Describe the expected behavior

Fix the import error.

Steps to reproduce the issue

1. >>> from mindspore.dataset import text
2. >>> text.__all__
3. >>> text.PythonTokenizer

Related log / screenshot

Special notes for this issue

[leonwanghui]

This issue has been fixed by PR #14518, so will close it.