doc for batched graph

docs/source/api/python/batch.rst

+dgl.BatchedDGLGraph
+-------------------
+.. autoclass:: dgl.BatchedDGLGraph
+    :members:
+    :show-inheritance:
+
+.. autofunction:: dgl.batch
+
+.. autofunction:: dgl.unbatch

docs/source/api/python/index.rst

@@ -5,3 +5,4 @@ Python APIs
    :maxdepth: 2
 
    graph
+   batch

python/dgl/__init__.py

@@ -9,7 +9,7 @@ from ._ffi.function import register_func, get_global_func, list_global_func_name
 from ._ffi.base import DGLError, __version__
 
 from .base import ALL
-from .batch import batch, unbatch
+from .batched_graph import *
 from .generator import *
 from .graph import DGLGraph, __MSG__, __REPR__
 from .subgraph import DGLSubGraph

python/dgl/batch.py → python/dgl/batched_graph.py

@@ -10,6 +10,8 @@ from . import graph_index as gi
 from . import backend as F
 from . import utils
 
+__all__ = ['BatchedDGLGraph', 'batch', 'unbatch', 'split']
+
 class BatchedDGLGraph(DGLGraph):
     """The batched DGL graph.
 
@@ -146,7 +148,7 @@ def split(graph_batch, num_or_size_splits):
     pass
 
 def unbatch(graph):
-    """Unbatch the graph and return a list of subgraphs.
+    """Unbatch and return the list of graphs in this batch.
 
     Parameters
     ----------

python/dgl/subgraph.py

@@ -6,7 +6,6 @@ import networkx as nx
 from . import backend as F
 from .frame import Frame, FrameRef
 from .graph import DGLGraph
-from .nx_adapt import nx_init
 from . import utils
 
 class DGLSubGraph(DGLGraph):