diff --git a/docs/Makefile b/docs/Makefile
index 2b4de2d8..b9f1cf95 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -14,7 +14,7 @@ help:
 	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 apidoc:
-	$(SPHINXAPIDOC) -efM -o source ../$(SPHINXPROJ)
+	$(SPHINXAPIDOC) -efM -o source ../$(SPHINXPROJ) && python3 format.py
 
 server:
 	cd build/html && python -m http.server
diff --git a/docs/format.py b/docs/format.py
new file mode 100644
index 00000000..7cc341c2
--- /dev/null
+++ b/docs/format.py
@@ -0,0 +1,65 @@
+import os
+
+
+def shorten(file, to_delete, cut=False):
+    if file.endswith("index.rst") or file.endswith("conf.py"):
+        return
+    res = []
+    with open(file, "r") as fin:
+        lines = fin.readlines()
+    for line in lines:
+        if cut and line.rstrip() == "Submodules":
+            break
+        else:
+            res.append(line.rstrip())
+    for i, line in enumerate(res):
+        if line.endswith(" package"):
+            res[i] = res[i][:-len(" package")]
+            res[i + 1] = res[i + 1][:-len(" package")]
+        elif line.endswith(" module"):
+            res[i] = res[i][:-len(" module")]
+            res[i + 1] = res[i + 1][:-len(" module")]
+        else:
+            for name in to_delete:
+                if line.endswith(name):
+                    res[i] = "del"
+
+    with open(file, "w") as fout:
+        for line in res:
+            if line != "del":
+                print(line, file=fout)
+
+
+def clear(path='./source/'):
+    files = os.listdir(path)
+    to_delete = [
+        "fastNLP.core.dist_trainer",
+        "fastNLP.core.predictor",
+
+        "fastNLP.io.file_reader",
+        "fastNLP.io.config_io",
+
+        "fastNLP.embeddings.contextual_embedding",
+
+        "fastNLP.modules.dropout",
+        "fastNLP.models.base_model",
+        "fastNLP.models.bert",
+        "fastNLP.models.enas_utils",
+        "fastNLP.models.enas_controller",
+        "fastNLP.models.enas_model",
+        "fastNLP.models.enas_trainer",
+    ]
+    for file in files:
+        if not os.path.isdir(path + file):
+            res = file.split('.')
+            if len(res) > 4:
+                to_delete.append(file[:-4])
+            elif len(res) == 4:
+                shorten(path + file, to_delete, True)
+            else:
+                shorten(path + file, to_delete)
+    for file in to_delete:
+        os.remove(path + file + ".rst")
+
+
+clear()
diff --git a/docs/source/fastNLP.core.rst b/docs/source/fastNLP.core.rst
index cacc6622..08d161b7 100644
--- a/docs/source/fastNLP.core.rst
+++ b/docs/source/fastNLP.core.rst
@@ -6,11 +6,10 @@ fastNLP.core
    :undoc-members:
    :show-inheritance:
 
-子模块
+Submodules
 ----------
 
 .. toctree::
-   :maxdepth: 1
 
    fastNLP.core.batch
    fastNLP.core.callback
diff --git a/docs/source/fastNLP.embeddings.rst b/docs/source/fastNLP.embeddings.rst
index 6b168906..6872e91d 100644
--- a/docs/source/fastNLP.embeddings.rst
+++ b/docs/source/fastNLP.embeddings.rst
@@ -6,11 +6,10 @@ fastNLP.embeddings
    :undoc-members:
    :show-inheritance:
 
-子模块
+Submodules
 ----------
 
 .. toctree::
-   :maxdepth: 1
 
    fastNLP.embeddings.bert_embedding
    fastNLP.embeddings.char_embedding
diff --git a/docs/source/fastNLP.io.data_loader.rst b/docs/source/fastNLP.io.data_loader.rst
index 8f990102..0b4f5d0b 100644
--- a/docs/source/fastNLP.io.data_loader.rst
+++ b/docs/source/fastNLP.io.data_loader.rst
@@ -1,7 +1,8 @@
 fastNLP.io.data\_loader
-==========================
+=======================
 
 .. automodule:: fastNLP.io.data_loader
    :members:
    :undoc-members:
-   :show-inheritance:
\ No newline at end of file
+   :show-inheritance:
+
diff --git a/docs/source/fastNLP.io.file_utils.rst b/docs/source/fastNLP.io.file_utils.rst
new file mode 100644
index 00000000..944550d7
--- /dev/null
+++ b/docs/source/fastNLP.io.file_utils.rst
@@ -0,0 +1,7 @@
+fastNLP.io.file\_utils
+======================
+
+.. automodule:: fastNLP.io.file_utils
+   :members:
+   :undoc-members:
+   :show-inheritance:
diff --git a/docs/source/fastNLP.io.loader.rst b/docs/source/fastNLP.io.loader.rst
new file mode 100644
index 00000000..bbdc1d7a
--- /dev/null
+++ b/docs/source/fastNLP.io.loader.rst
@@ -0,0 +1,8 @@
+fastNLP.io.loader
+=================
+
+.. automodule:: fastNLP.io.loader
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
diff --git a/docs/source/fastNLP.io.pipe.rst b/docs/source/fastNLP.io.pipe.rst
new file mode 100644
index 00000000..bf126585
--- /dev/null
+++ b/docs/source/fastNLP.io.pipe.rst
@@ -0,0 +1,8 @@
+fastNLP.io.pipe
+===============
+
+.. automodule:: fastNLP.io.pipe
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
diff --git a/docs/source/fastNLP.io.rst b/docs/source/fastNLP.io.rst
index a97ed67d..0a006709 100644
--- a/docs/source/fastNLP.io.rst
+++ b/docs/source/fastNLP.io.rst
@@ -6,14 +6,23 @@ fastNLP.io
    :undoc-members:
    :show-inheritance:
 
-子模块
+Subpackages
+-----------
+
+.. toctree::
+
+   fastNLP.io.data_loader
+   fastNLP.io.loader
+   fastNLP.io.pipe
+
+Submodules
 ----------
 
 .. toctree::
-   :maxdepth: 1
 
    fastNLP.io.base_loader
-   fastNLP.io.embed_loader
    fastNLP.io.dataset_loader
-   fastNLP.io.data_loader
+   fastNLP.io.embed_loader
+   fastNLP.io.file_utils
    fastNLP.io.model_io
+   fastNLP.io.utils
diff --git a/docs/source/fastNLP.io.utils.rst b/docs/source/fastNLP.io.utils.rst
new file mode 100644
index 00000000..0b3f3938
--- /dev/null
+++ b/docs/source/fastNLP.io.utils.rst
@@ -0,0 +1,7 @@
+fastNLP.io.utils
+================
+
+.. automodule:: fastNLP.io.utils
+   :members:
+   :undoc-members:
+   :show-inheritance:
diff --git a/docs/source/fastNLP.models.rst b/docs/source/fastNLP.models.rst
index 2ea546e2..36875b85 100644
--- a/docs/source/fastNLP.models.rst
+++ b/docs/source/fastNLP.models.rst
@@ -6,11 +6,10 @@ fastNLP.models
    :undoc-members:
    :show-inheritance:
 
-子模块
+Submodules
 ----------
 
 .. toctree::
-   :maxdepth: 1
 
    fastNLP.models.biaffine_parser
    fastNLP.models.cnn_text_classification
diff --git a/docs/source/fastNLP.modules.encoder.rst b/docs/source/fastNLP.modules.encoder.rst
index 0562f12d..e60f9fa4 100644
--- a/docs/source/fastNLP.modules.encoder.rst
+++ b/docs/source/fastNLP.modules.encoder.rst
@@ -5,3 +5,4 @@ fastNLP.modules.encoder
    :members:
    :undoc-members:
    :show-inheritance:
+
diff --git a/docs/source/fastNLP.modules.rst b/docs/source/fastNLP.modules.rst
index 646ef2d3..06494b53 100644
--- a/docs/source/fastNLP.modules.rst
+++ b/docs/source/fastNLP.modules.rst
@@ -6,12 +6,17 @@ fastNLP.modules
    :undoc-members:
    :show-inheritance:
 
-子模块
+Subpackages
 -----------
 
 .. toctree::
-   :titlesonly:
-   :maxdepth: 1
 
    fastNLP.modules.decoder
-   fastNLP.modules.encoder
\ No newline at end of file
+   fastNLP.modules.encoder
+
+Submodules
+----------
+
+.. toctree::
+
+   fastNLP.modules.utils
diff --git a/docs/source/fastNLP.modules.utils.rst b/docs/source/fastNLP.modules.utils.rst
new file mode 100644
index 00000000..c0219435
--- /dev/null
+++ b/docs/source/fastNLP.modules.utils.rst
@@ -0,0 +1,7 @@
+fastNLP.modules.utils
+=====================
+
+.. automodule:: fastNLP.modules.utils
+   :members:
+   :undoc-members:
+   :show-inheritance:
diff --git a/docs/source/fastNLP.rst b/docs/source/fastNLP.rst
index 0057a184..e3ba429d 100644
--- a/docs/source/fastNLP.rst
+++ b/docs/source/fastNLP.rst
@@ -1,16 +1,15 @@
-API 文档
-===============
+fastNLP
+=======
 
 .. automodule:: fastNLP
    :members:
    :undoc-members:
    :show-inheritance:
 
-内部模块
+Subpackages
 -----------
 
 .. toctree::
-   :maxdepth: 1
 
    fastNLP.core
    fastNLP.embeddings
diff --git a/docs/source/modules.rst b/docs/source/modules.rst
index 9ca3c7f3..e9a92cb7 100644
--- a/docs/source/modules.rst
+++ b/docs/source/modules.rst
@@ -2,7 +2,6 @@ fastNLP
 =======
 
 .. toctree::
-   :titlesonly:
    :maxdepth: 4
 
    fastNLP
diff --git a/fastNLP/core/dist_trainer.py b/fastNLP/core/dist_trainer.py
index 4a423933..00db6361 100644
--- a/fastNLP/core/dist_trainer.py
+++ b/fastNLP/core/dist_trainer.py
@@ -1,3 +1,6 @@
+"""
+正在开发中的分布式训练代码
+"""
 import torch
 import torch.cuda
 import torch.optim
@@ -41,7 +44,8 @@ def get_local_rank():
 
 
 class DistTrainer():
-    """Distributed Trainer that support distributed and mixed precision training
+    """
+    Distributed Trainer that support distributed and mixed precision training
     """
     def __init__(self, train_data, model, optimizer=None, loss=None,
                  callbacks_all=None, callbacks_master=None,
diff --git a/fastNLP/embeddings/bert_embedding.py b/fastNLP/embeddings/bert_embedding.py
index ea5e84ac..723cd2d5 100644
--- a/fastNLP/embeddings/bert_embedding.py
+++ b/fastNLP/embeddings/bert_embedding.py
@@ -176,9 +176,9 @@ class BertWordPieceEncoder(nn.Module):
     def index_datasets(self, *datasets, field_name, add_cls_sep=True):
         """
         使用bert的tokenizer新生成word_pieces列加入到datasets中，并将他们设置为input,且将word_pieces这一列的pad value设置为了
-            bert的pad value。
+        bert的pad value。
 
-        :param DataSet datasets: DataSet对象
+        :param ~fastNLP.DataSet datasets: DataSet对象
         :param str field_name: 基于哪一列的内容生成word_pieces列。这一列中每个数据应该是List[str]的形式。
         :param bool add_cls_sep: 如果首尾不是[CLS]与[SEP]会在首尾额外加入[CLS]与[SEP]。
         :return:
diff --git a/fastNLP/embeddings/contextual_embedding.py b/fastNLP/embeddings/contextual_embedding.py
index 1831af4e..152b0ab9 100644
--- a/fastNLP/embeddings/contextual_embedding.py
+++ b/fastNLP/embeddings/contextual_embedding.py
@@ -1,4 +1,3 @@
-
 from abc import abstractmethod
 import torch
 
@@ -9,6 +8,10 @@ from ..core.sampler import SequentialSampler
 from ..core.utils import _move_model_to_device, _get_model_device
 from .embedding import TokenEmbedding
 
+__all__ = [
+    "ContextualEmbedding"
+]
+
 
 class ContextualEmbedding(TokenEmbedding):
     def __init__(self, vocab: Vocabulary, word_dropout:float=0.0, dropout:float=0.0):
diff --git a/fastNLP/io/__init__.py b/fastNLP/io/__init__.py
index cd0d3527..bf5c2c36 100644
--- a/fastNLP/io/__init__.py
+++ b/fastNLP/io/__init__.py
@@ -14,27 +14,56 @@
 __all__ = [
     'EmbedLoader',
 
-    'CSVLoader',
-    'JsonLoader',
-
     'DataBundle',
     'DataSetLoader',
 
-    'ConllLoader',
-    'Conll2003Loader',
+    'YelpLoader',
+    'YelpFullLoader',
+    'YelpPolarityLoader',
     'IMDBLoader',
-    'MatchingLoader',
-    'SNLILoader',
-    'MNLILoader',
-    'MTL16Loader',
-    'PeopleDailyCorpusLoader',
-    'QNLILoader',
-    'QuoraLoader',
-    'RTELoader',
     'SSTLoader',
     'SST2Loader',
-    'YelpLoader',
-    
+
+    'ConllLoader',
+    'Conll2003Loader',
+    'Conll2003NERLoader',
+    'OntoNotesNERLoader',
+    'CTBLoader',
+
+    'Loader',
+    'CSVLoader',
+    'JsonLoader',
+
+    'CWSLoader',
+
+    'MNLILoader',
+    "QuoraLoader",
+    "SNLILoader",
+    "QNLILoader",
+    "RTELoader",
+
+    "YelpFullPipe",
+    "YelpPolarityPipe",
+    "SSTPipe",
+    "SST2Pipe",
+    "IMDBPipe",
+
+    "Conll2003NERPipe",
+    "OntoNotesNERPipe",
+
+    "MatchingBertPipe",
+    "RTEBertPipe",
+    "SNLIBertPipe",
+    "QuoraBertPipe",
+    "QNLIBertPipe",
+    "MNLIBertPipe",
+    "MatchingPipe",
+    "RTEPipe",
+    "SNLIPipe",
+    "QuoraPipe",
+    "QNLIPipe",
+    "MNLIPipe",
+
     'ModelLoader',
     'ModelSaver',
 ]
@@ -44,4 +73,5 @@ from .base_loader import DataBundle, DataSetLoader
 from .dataset_loader import CSVLoader, JsonLoader
 from .model_io import ModelLoader, ModelSaver
 
-from .data_loader import *
+from .loader import *
+from .pipe import *
diff --git a/fastNLP/io/base_loader.py b/fastNLP/io/base_loader.py
index 01232627..429a8406 100644
--- a/fastNLP/io/base_loader.py
+++ b/fastNLP/io/base_loader.py
@@ -128,7 +128,7 @@ class DataBundle:
         """
         向DataBunlde中增加vocab
 
-        :param Vocabulary vocab: 词表
+        :param ~fastNLP.Vocabulary vocab: 词表
         :param str field_name: 这个vocab对应的field名称
         :return:
         """
@@ -138,7 +138,7 @@ class DataBundle:
     def set_dataset(self, dataset, name):
         """
 
-        :param DataSet dataset: 传递给DataBundle的DataSet
+        :param ~fastNLP.DataSet dataset: 传递给DataBundle的DataSet
         :param str name: dataset的名称
         :return:
         """
diff --git a/fastNLP/io/config_io.py b/fastNLP/io/config_io.py
index 4acdbb96..ac349080 100644
--- a/fastNLP/io/config_io.py
+++ b/fastNLP/io/config_io.py
@@ -1,7 +1,9 @@
 """
 用于读入和处理和保存 config 文件
- .. todo::
+
+.. todo::
     这个模块中的类可能被抛弃？
+
 """
 __all__ = [
     "ConfigLoader",
diff --git a/fastNLP/io/file_utils.py b/fastNLP/io/file_utils.py
index b465ed9b..43fe2ab1 100644
--- a/fastNLP/io/file_utils.py
+++ b/fastNLP/io/file_utils.py
@@ -84,6 +84,7 @@ def cached_path(url_or_filename:str, cache_dir:str=None, name=None) -> Path:
     给定一个url，尝试通过url中的解析出来的文件名字filename到{cache_dir}/{name}/{filename}下寻找这个文件，
         (1)如果cache_dir=None, 则cache_dir=~/.fastNLP/; 否则cache_dir=cache_dir
         (2)如果name=None, 则没有中间的{name}这一层结构；否者中间结构就为{name}
+
     如果有该文件，就直接返回路径
     如果没有该文件，则尝试用传入的url下载
 
@@ -126,8 +127,10 @@ def get_filepath(filepath):
     如果filepath为文件夹，
         如果内含多个文件, 返回filepath
         如果只有一个文件, 返回filepath + filename
+
     如果filepath为文件
         返回filepath
+
     :param str filepath: 路径
     :return:
     """
@@ -237,7 +240,8 @@ def split_filename_suffix(filepath):
 def get_from_cache(url: str, cache_dir: Path = None) -> Path:
     """
     尝试在cache_dir中寻找url定义的资源; 如果没有找到; 则从url下载并将结果放在cache_dir下，缓存的名称由url的结果推断而来。会将下载的
-        文件解压，将解压后的文件全部放在cache_dir文件夹中。
+    文件解压，将解压后的文件全部放在cache_dir文件夹中。
+
     如果从url中下载的资源解压后有多个文件，则返回目录的路径; 如果只有一个资源文件，则返回具体的路径。
     """
     cache_dir.mkdir(parents=True, exist_ok=True)
diff --git a/fastNLP/io/loader/__init__.py b/fastNLP/io/loader/__init__.py
index 8e436532..8c0d391c 100644
--- a/fastNLP/io/loader/__init__.py
+++ b/fastNLP/io/loader/__init__.py
@@ -1,30 +1,61 @@
-
 """
-Loader用于读取数据，并将内容读取到 :class:`~fastNLP.DataSet` 或者 :class:`~fastNLP.io.DataBundle`中。所有的Loader都支持以下的
-    三个方法： __init__()，_load(), loads(). 其中__init__()用于申明读取参数，以及说明该Loader支持的数据格式，读取后Dataset中field
-    ; _load(path)方法传入一个文件路径读取单个文件，并返回DataSet; load(paths)用于读取文件夹下的文件，并返回DataBundle, load()方法
-    支持以下三种类型的参数
+Loader用于读取数据，并将内容读取到 :class:`~fastNLP.DataSet` 或者 :class:`~fastNLP.io.DataBundle` 中。所有的Loader都支持以下的
+三个方法： __init__()，_load(), loads(). 其中__init__()用于申明读取参数，以及说明该Loader支持的数据格式，读取后Dataset中field
+; _load(path)方法传入一个文件路径读取单个文件，并返回DataSet; load(paths)用于读取文件夹下的文件，并返回DataBundle, load()方法
+支持以下三种类型的参数::
 
-    Example::
-        (0) 如果传入None，将尝试自动下载数据集并缓存。但不是所有的数据都可以直接下载。
-        (1) 如果传入的是一个文件path，则返回的DataBundle包含一个名为train的DataSet可以通过data_bundle.datasets['train']获取
-		(2) 传入的是一个文件夹目录，将读取的是这个文件夹下文件名中包含'train', 'test', 'dev'的文件，其它文件会被忽略。
-			假设某个目录下的文件为
-				-train.txt
-				-dev.txt
-				-test.txt
-				-other.txt
-			Loader().load('/path/to/dir')读取，返回的data_bundle中可以用data_bundle.datasets['train'], data_bundle.datasets['dev'],
-			    data_bundle.datasets['test']获取对应的DataSet，其中other.txt的内容会被忽略。
-			假设某个目录下的文件为
-				-train.txt
-				-dev.txt
-			Loader().load('/path/to/dir')读取，返回的data_bundle中可以用data_bundle.datasets['train'], data_bundle.datasets['dev']获取
-				对应的DataSet。
-		(3) 传入一个dict，key为dataset的名称，value是该dataset的文件路径。
-			paths = {'train':'/path/to/train', 'dev': '/path/to/dev', 'test':'/path/to/test'}
-			Loader().load(paths)  # 返回的data_bundle可以通过以下的方式获取相应的DataSet, data_bundle.datasets['train'], data_bundle.datasets['dev'],
-				data_bundle.datasets['test']
+    (0) 如果传入None，将尝试自动下载数据集并缓存。但不是所有的数据都可以直接下载。
+    (1) 如果传入的是一个文件path，则返回的DataBundle包含一个名为train的DataSet可以通过data_bundle.datasets['train']获取
+    (2) 传入的是一个文件夹目录，将读取的是这个文件夹下文件名中包含'train', 'test', 'dev'的文件，其它文件会被忽略。
+        假设某个目录下的文件为
+            -train.txt
+            -dev.txt
+            -test.txt
+            -other.txt
+        Loader().load('/path/to/dir')读取，返回的data_bundle中可以用data_bundle.datasets['train'], data_bundle.datasets['dev'],
+            data_bundle.datasets['test']获取对应的DataSet，其中other.txt的内容会被忽略。
+        假设某个目录下的文件为
+            -train.txt
+            -dev.txt
+        Loader().load('/path/to/dir')读取，返回的data_bundle中可以用data_bundle.datasets['train'], data_bundle.datasets['dev']获取
+            对应的DataSet。
+    (3) 传入一个dict，key为dataset的名称，value是该dataset的文件路径。
+        paths = {'train':'/path/to/train', 'dev': '/path/to/dev', 'test':'/path/to/test'}
+        Loader().load(paths)  # 返回的data_bundle可以通过以下的方式获取相应的DataSet, data_bundle.datasets['train'], data_bundle.datasets['dev'],
+            data_bundle.datasets['test']
 
 """
 
+__all__ = [
+    'YelpLoader',
+    'YelpFullLoader',
+    'YelpPolarityLoader',
+    'IMDBLoader',
+    'SSTLoader',
+    'SST2Loader',
+
+    'ConllLoader',
+    'Conll2003Loader',
+    'Conll2003NERLoader',
+    'OntoNotesNERLoader',
+    'CTBLoader',
+
+    'Loader',
+    'CSVLoader',
+    'JsonLoader',
+
+    'CWSLoader',
+
+    'MNLILoader',
+    "QuoraLoader",
+    "SNLILoader",
+    "QNLILoader",
+    "RTELoader"
+]
+from .classification import YelpLoader, YelpFullLoader, YelpPolarityLoader, IMDBLoader, SSTLoader, SST2Loader
+from .conll import ConllLoader, Conll2003Loader, Conll2003NERLoader, OntoNotesNERLoader, CTBLoader
+from .csv import CSVLoader
+from .cws import CWSLoader
+from .json import JsonLoader
+from .loader import Loader
+from .matching import MNLILoader, QuoraLoader, SNLILoader, QNLILoader, RTELoader
diff --git a/fastNLP/io/loader/conll.py b/fastNLP/io/loader/conll.py
index 43790c15..b2c89ecc 100644
--- a/fastNLP/io/loader/conll.py
+++ b/fastNLP/io/loader/conll.py
@@ -1,12 +1,12 @@
 from typing import Dict, Union
 
 from .loader import Loader
-from ... import DataSet
+from ...core.dataset import DataSet
 from ..file_reader import _read_conll
-from ... import Instance
+from ...core.instance import Instance
 from .. import DataBundle
 from ..utils import check_loader_paths
-from ... import Const
+from ...core.const import Const
 
 
 class ConllLoader(Loader):
diff --git a/fastNLP/io/loader/cws.py b/fastNLP/io/loader/cws.py
index 46c07f28..3af28116 100644
--- a/fastNLP/io/loader/cws.py
+++ b/fastNLP/io/loader/cws.py
@@ -1,6 +1,6 @@
-
 from .loader import Loader
-from ...core import DataSet, Instance
+from ...core.dataset import DataSet
+from ...core.instance import Instance
 
 
 class CWSLoader(Loader):
diff --git a/fastNLP/io/loader/loader.py b/fastNLP/io/loader/loader.py
index 4cf5bcf3..c59de29f 100644
--- a/fastNLP/io/loader/loader.py
+++ b/fastNLP/io/loader/loader.py
@@ -1,4 +1,4 @@
-from ... import DataSet
+from ...core.dataset import DataSet
 from .. import DataBundle
 from ..utils import check_loader_paths
 from typing import Union, Dict
diff --git a/fastNLP/io/loader/matching.py b/fastNLP/io/loader/matching.py
index eff98ba3..58fa0d6f 100644
--- a/fastNLP/io/loader/matching.py
+++ b/fastNLP/io/loader/matching.py
@@ -1,19 +1,12 @@
-
 import warnings
 from .loader import Loader
 from .json import JsonLoader
-from ...core import Const
+from ...core.const import Const
 from .. import DataBundle
 import os
 from typing import Union, Dict
-from ...core import DataSet
-from ...core import Instance
-
-__all__ = ['MNLILoader',
-           "QuoraLoader",
-           "SNLILoader",
-           "QNLILoader",
-           "RTELoader"]
+from ...core.dataset import DataSet
+from ...core.instance import Instance
 
 
 class MNLILoader(Loader):
diff --git a/fastNLP/io/pipe/__init__.py b/fastNLP/io/pipe/__init__.py
index 0cf8d949..4cec3ad5 100644
--- a/fastNLP/io/pipe/__init__.py
+++ b/fastNLP/io/pipe/__init__.py
@@ -1,8 +1,34 @@
-
-
 """
 Pipe用于处理数据，所有的Pipe都包含一个process(DataBundle)方法，传入一个DataBundle对象, 在传入DataBundle上进行原位修改，并将其返回；
-    process_from_file(paths)传入的文件路径，返回一个DataBundle。process(DataBundle)或者process_from_file(paths)的返回DataBundle
-    中的DataSet一般都包含原文与转换为index的输入，以及转换为index的target；除了DataSet之外，还会包含将field转为index时所建立的词表。
+process_from_file(paths)传入的文件路径，返回一个DataBundle。process(DataBundle)或者process_from_file(paths)的返回DataBundle
+中的DataSet一般都包含原文与转换为index的输入，以及转换为index的target；除了DataSet之外，还会包含将field转为index时所建立的词表。
+
+"""
+__all__ = [
+    "YelpFullPipe",
+    "YelpPolarityPipe",
+    "SSTPipe",
+    "SST2Pipe",
+    "IMDBPipe",
+
+    "Conll2003NERPipe",
+    "OntoNotesNERPipe",
+
+    "MatchingBertPipe",
+    "RTEBertPipe",
+    "SNLIBertPipe",
+    "QuoraBertPipe",
+    "QNLIBertPipe",
+    "MNLIBertPipe",
+    "MatchingPipe",
+    "RTEPipe",
+    "SNLIPipe",
+    "QuoraPipe",
+    "QNLIPipe",
+    "MNLIPipe",
+]
 
-"""
\ No newline at end of file
+from .classification import YelpFullPipe, YelpPolarityPipe, SSTPipe, SST2Pipe, IMDBPipe
+from .conll import Conll2003NERPipe, OntoNotesNERPipe
+from .matching import MatchingBertPipe, RTEBertPipe, SNLIBertPipe, QuoraBertPipe, QNLIBertPipe, MNLIBertPipe, \
+    MatchingPipe, RTEPipe, SNLIPipe, QuoraPipe, QNLIPipe, MNLIPipe
diff --git a/fastNLP/io/pipe/classification.py b/fastNLP/io/pipe/classification.py
index a64e5328..429b6552 100644
--- a/fastNLP/io/pipe/classification.py
+++ b/fastNLP/io/pipe/classification.py
@@ -1,17 +1,17 @@
-
 from nltk import Tree
 
 from ..base_loader import DataBundle
 from ...core.vocabulary import Vocabulary
 from ...core.const import Const
 from ..loader.classification import IMDBLoader, YelpFullLoader, SSTLoader, SST2Loader, YelpPolarityLoader
-from ...core import DataSet, Instance
+from ...core.dataset import DataSet
+from ...core.instance import Instance
 
 from .utils import get_tokenizer, _indexize, _add_words_field, _drop_empty_instance
 from .pipe import Pipe
 import re
 nonalpnum = re.compile('[^0-9a-zA-Z?!\']+')
-from ...core import cache_results
+from ...core.utils import cache_results
 
 class _CLSPipe(Pipe):
     """
@@ -257,7 +257,7 @@ class SSTPipe(_CLSPipe):
             "(4 (4 (2 Offers) (3 (3 (2 that) (3 (3 rare)..."
             "..."
 
-        :param DataBundle data_bundle: 需要处理的DataBundle对象
+        :param ~fastNLP.io.DataBundle data_bundle: 需要处理的DataBundle对象
         :return:
         """
         #  先取出subtree
@@ -407,7 +407,7 @@ class IMDBPipe(_CLSPipe):
 
         :param DataBunlde data_bundle: 传入的DataBundle中的DataSet必须包含raw_words和target两个field，且raw_words列应该为str,
             target列应该为str。
-        :return:DataBundle
+        :return: DataBundle
         """
         # 替换<br />
         def replace_br(raw_words):
diff --git a/fastNLP/io/pipe/conll.py b/fastNLP/io/pipe/conll.py
index 4f780614..b9007344 100644
--- a/fastNLP/io/pipe/conll.py
+++ b/fastNLP/io/pipe/conll.py
@@ -1,7 +1,7 @@
 from .pipe import Pipe
 from .. import DataBundle
 from .utils import iob2, iob2bioes
-from ... import Const
+from ...core.const import Const
 from ..loader.conll import Conll2003NERLoader, OntoNotesNERLoader
 from .utils import _indexize, _add_words_field
 
@@ -19,15 +19,16 @@ class _NERPipe(Pipe):
     :param bool lower: 是否将words小写化后再建立词表，绝大多数情况都不需要设置为True。
     :param int target_pad_val: target的padding值，target这一列pad的位置值为target_pad_val。默认为-100。
     """
-    def __init__(self, encoding_type:str='bio', lower:bool=False, target_pad_val=0):
-        if  encoding_type == 'bio':
+
+    def __init__(self, encoding_type: str = 'bio', lower: bool = False, target_pad_val=0):
+        if encoding_type == 'bio':
             self.convert_tag = iob2
         else:
             self.convert_tag = iob2bioes
         self.lower = lower
         self.target_pad_val = int(target_pad_val)
 
-    def process(self, data_bundle:DataBundle)->DataBundle:
+    def process(self, data_bundle: DataBundle) -> DataBundle:
         """
         支持的DataSet的field为
 
@@ -146,4 +147,3 @@ class OntoNotesNERPipe(_NERPipe):
     def process_from_file(self, paths):
         data_bundle = OntoNotesNERLoader().load(paths)
         return self.process(data_bundle)
-
diff --git a/fastNLP/io/pipe/matching.py b/fastNLP/io/pipe/matching.py
index 76a0eaf7..93e854b1 100644
--- a/fastNLP/io/pipe/matching.py
+++ b/fastNLP/io/pipe/matching.py
@@ -2,10 +2,11 @@ import math
 
 from .pipe import Pipe
 from .utils import get_tokenizer
-from ...core import Const
-from ...core import Vocabulary
+from ...core.const import Const
+from ...core.vocabulary import Vocabulary
 from ..loader.matching import SNLILoader, MNLILoader, QNLILoader, RTELoader, QuoraLoader
 
+
 class MatchingBertPipe(Pipe):
     """
     Matching任务的Bert pipe，输出的DataSet将包含以下的field
diff --git a/fastNLP/io/pipe/pipe.py b/fastNLP/io/pipe/pipe.py
index 14c3866a..76cc00ec 100644
--- a/fastNLP/io/pipe/pipe.py
+++ b/fastNLP/io/pipe/pipe.py
@@ -1,9 +1,9 @@
-
 from .. import DataBundle
 
+
 class Pipe:
-    def process(self, data_bundle:DataBundle)->DataBundle:
+    def process(self, data_bundle: DataBundle) -> DataBundle:
         raise NotImplementedError
 
-    def process_from_file(self, paths)->DataBundle:
+    def process_from_file(self, paths) -> DataBundle:
         raise NotImplementedError
diff --git a/fastNLP/io/pipe/utils.py b/fastNLP/io/pipe/utils.py
index 59bee96e..5e9ff8dc 100644
--- a/fastNLP/io/pipe/utils.py
+++ b/fastNLP/io/pipe/utils.py
@@ -1,6 +1,6 @@
 from typing import List
-from ...core import Vocabulary
-from ...core import Const
+from ...core.vocabulary import Vocabulary
+from ...core.const import Const
 
 def iob2(tags:List[str])->List[str]:
     """
diff --git a/fastNLP/io/utils.py b/fastNLP/io/utils.py
index a4ca2954..76b32b0a 100644
--- a/fastNLP/io/utils.py
+++ b/fastNLP/io/utils.py
@@ -6,12 +6,14 @@ from pathlib import Path
 
 def check_loader_paths(paths:Union[str, Dict[str, str]])->Dict[str, str]:
     """
-    检查传入dataloader的文件的合法性。如果为合法路径，将返回至少包含'train'这个key的dict。类似于下面的结果
-    {
-        'train': '/some/path/to/', # 一定包含，建词表应该在这上面建立，剩下的其它文件应该只需要处理并index。
-        'test': 'xxx' # 可能有，也可能没有
-        ...
-    }
+    检查传入dataloader的文件的合法性。如果为合法路径，将返回至少包含'train'这个key的dict。类似于下面的结果::
+
+        {
+            'train': '/some/path/to/', # 一定包含，建词表应该在这上面建立，剩下的其它文件应该只需要处理并index。
+            'test': 'xxx' # 可能有，也可能没有
+            ...
+        }
+
     如果paths为不合法的，将直接进行raise相应的错误. 如果paths内不包含train也会报错。
 
     :param str paths: 路径. 可以为一个文件路径(则认为该文件就是train的文件); 可以为一个文件目录，将在该目录下寻找train(文件名
diff --git a/fastNLP/modules/utils.py b/fastNLP/modules/utils.py
index 21608c5d..ead75711 100644
--- a/fastNLP/modules/utils.py
+++ b/fastNLP/modules/utils.py
@@ -112,7 +112,7 @@ def get_dropout_mask(drop_p: float, tensor: torch.Tensor):
     根据tensor的形状，生成一个mask
 
     :param drop_p: float, 以多大的概率置为0。
-    :param tensor:torch.Tensor
+    :param tensor: torch.Tensor
     :return: torch.FloatTensor. 与tensor一样的shape
     """
     mask_x = torch.ones_like(tensor)
diff --git a/reproduction/seqence_labelling/chinese_ner/data/ChineseNER.py b/reproduction/seqence_labelling/chinese_ner/data/ChineseNER.py
index cec5ab76..0d292bdc 100644
--- a/reproduction/seqence_labelling/chinese_ner/data/ChineseNER.py
+++ b/reproduction/seqence_labelling/chinese_ner/data/ChineseNER.py
@@ -51,7 +51,7 @@ class ChineseNERLoader(DataSetLoader):
         :param paths:
         :param bool, bigrams: 是否包含生成bigram feature, [a, b, c, d] -> [ab, bc, cd, d<eos>]
         :param bool, trigrams: 是否包含trigram feature，[a, b, c, d] -> [abc, bcd, cd<eos>, d<eos><eos>]
-        :return: DataBundle
+        :return: ~fastNLP.io.DataBundle
             包含以下的fields
                 raw_chars: List[str]
                 chars: List[int]