module 'torchtext.data' has no attribute 'Iterator'
AttributeError: module 'torchtext.data' has no attribute 'Dataset'
AttributeError: module 'torchtext.data' has no attribute 'Field'
AttributeError: module 'torchtext.data' has no attribute 'Example'
torchtext0.9以上版本变化：
- torchtext.data.Pipeline -> torchtext.legacy.data.Pipeline
- torchtext.data.Batch -> torchtext.legacy.data.Batch
- torchtext.data.Example -> torchtext.legacy.data.Example
- torchtext.data.Field -> torchtext.legacy.data.Field
- torchtext.data.Iterator -> torchtext.legacy.data.Iterator
- torchtext.data.Dataset -> torchtext.legacy.data.Dataset
