doc: refine English description

Author: chenwhql

paddle/fluid/operators/sequence_enumerate_op.cc

@@ -50,24 +50,23 @@ class SequenceEnumerateOpMaker : public framework::OpProtoAndCheckerMaker {
              "(2-D LoDTensor with the 2nd dimension equal to 1) "
              "Input LoDTensor of SequenceEnumerate operator.");
     AddOutput("Out",
-              "(2-D LoDTensor with the 2nd dimension equal to 1) "
+              "(2-D LoDTensor with the 2nd dimension equal to win_size) "
               "Output LoDTensor of SequenceEnumerate operator.");
     AddAttr<int>("win_size", "(int) The enumerate sequence window size.")
         .AddCustomChecker([](const int& win_size) {
           PADDLE_ENFORCE(win_size >= 2,
-                         "The window size should be greater than 2.");
+                         "The window size should be not less than 2.");
         });
     AddAttr<int>("pad_value", "(int) The enumerate sequence padding value.")
         .SetDefault(0);
     AddComment(R"DOC(
 Sequence Enumerate Operator.
 
-Sequence enumerate operator generate a new LoDTensor 
-with the same 1st dimension length as the original LoDTensor, 
-and with the 2nd dimension equal to the input window length, 
-the new sub-sequence on 2nd dimension is enumerated one by one on the original sequence.
-The values of the last insufficient part areall filled with the input pad_value.
-
+Generate a new sequence for the input index sequence, which enumerates all the
+sub-sequences with length win_size of the input. 
+The enumerated sequence has the same 1st dimension with variable input, and
+the 2nd dimension is win_size, padded by pad_value if necessary in generation.
+    
 Examples:
 Case 1:
   Input:

python/paddle/fluid/layers/nn.py

@@ -5522,13 +5522,12 @@ def flatten(x, axis=1, name=None):
     return out
 
 
-def sequence_enumerate(input, win_size, pad_value, name=None):
+def sequence_enumerate(input, win_size, pad_value=0, name=None):
     """
-    Generate a new LoDTensor 
-    with the same 1st dimension length as the original LoDTensor, 
-    and with the 2nd dimension equal to the input window length, 
-    the new sub-sequence on 2nd dimension is enumerated one by one on the original sequence.
-    The values of the last insufficient part areall filled with the input pad_value.
+    Generate a new sequence for the input index sequence, which enumerates all the
+    sub-sequences with length win_size of the input. 
+    The enumerated sequence has the same 1st dimension with variable input, and
+    the 2nd dimension is win_size, padded by pad_value if necessary in generation.
     
     Examples:
     Case 1:
@@ -5545,9 +5544,9 @@ def sequence_enumerate(input, win_size, pad_value, name=None):
         Out.dims = [5, 2]
 
     Args:
-        input (Variable): The input variable which is a LoDTensor
-        win_size (int): The enumerate sequence window size.
-        pad_value (int): The enumerate sequence padding value.
+        input (Variable): The input variable which is a index sequence.
+        win_size (int): The window size for enumerating all sub-sequences.
+        pad_value (int): The padding value, default 0.
 
     Returns:
         Variable: The enumerate sequence variable which is a LoDTensor.

python/paddle/fluid/tests/unittests/test_sequence_enumerate_op.py

@@ -68,6 +68,17 @@ def init_test_case(self):
         self.out_seq = np.array(out_seq).astype("int64")
 
 
+class TestSequenceEnumerateOpLargeWinSize(TestSequenceEnumerateOp):
+    def init_test_case(self):
+        self.in_seq = np.random.randint(0, 10, (30, 1)).astype("int32")
+        self.lod = [[9, 4, 11, 6]]
+        self.win_size = 5
+        self.pad_value = 0
+        out_seq = sequence_enumerate(self.in_seq, self.lod, self.win_size,
+                                     self.pad_value)
+        self.out_seq = np.array(out_seq).astype("int32")
+
+
 class TestSequenceEnumerateOpMaxWinSize(TestSequenceEnumerateOp):
     def init_test_case(self):
         self.in_seq = np.random.randint(0, 10, (30, 1)).astype("int32")
@@ -79,5 +90,16 @@ def init_test_case(self):
         self.out_seq = np.array(out_seq).astype("int32")
 
 
+class TestSequenceEnumerateOpLargePadValue(TestSequenceEnumerateOp):
+    def init_test_case(self):
+        self.in_seq = np.random.randint(0, 10, (30, 1)).astype("int32")
+        self.lod = [[9, 4, 11, 6]]
+        self.win_size = 5
+        self.pad_value = 5
+        out_seq = sequence_enumerate(self.in_seq, self.lod, self.win_size,
+                                     self.pad_value)
+        self.out_seq = np.array(out_seq).astype("int32")
+
+
 if __name__ == "__main__":
     unittest.main()