[scripts] Fix convert_nnet2_to_nnet3.py (kaldi-asr#1774)

Use 'execute_command' instead of 'run_kaldi_command' and correctly parse/convert SumGroupComponents

egs/wsj/s5/steps/nnet3/convert_nnet2_to_nnet3.py

@@ -179,16 +179,16 @@ def write_model(self, model, binary="true"):
             raise IOError("Config file {0} does not exist.".format(self.config))
 
         # write raw model
-        common_lib.run_kaldi_command("nnet3-init --binary=true {0} {1}"
+        common_lib.execute_command("nnet3-init --binary=true {0} {1}"
             .format(self.config, os.path.join(tmpdir, "nnet3.raw")))
 
         # add transition model
-        common_lib.run_kaldi_command("nnet3-am-init --binary=true {0} {1} {2}"
+        common_lib.execute_command("nnet3-am-init --binary=true {0} {1} {2}"
             .format(self.transition_model, os.path.join(tmpdir, "nnet3.raw"),
                     os.path.join(tmpdir, "nnet3_no_prior.mdl")))
 
         # add priors
-        common_lib.run_kaldi_command("nnet3-am-adjust-priors "
+        common_lib.execute_command("nnet3-am-adjust-priors "
                                      "--binary={0} {1} {2} {3}"
             .format(binary, os.path.join(tmpdir, "nnet3_no_prior.mdl"), 
                     self.priors, model))
@@ -270,6 +270,8 @@ def parse_component(line, line_buffer):
         pairs = parse_fixed_scale_component(component, line, line_buffer)
     elif component == "<FixedBiasComponent>":
         pairs = parse_fixed_bias_component(component, line, line_buffer)
+    elif component == "<SumGroupComponent>":
+        pairs = parse_sum_group_component(component, line, line_buffer)
     elif component in KNOWN_COMPONENTS:
         pairs = parse_standard_component(component, line, line_buffer)
     else:
@@ -300,6 +302,14 @@ def parse_fixed_scale_component(component, line, line_buffer):
 
     return {"<Scales>" : filename}
 
+def parse_sum_group_component(component, line, line_buffer):
+    line = consume_token(component, line)
+    line = consume_token("<Sizes>", line)
+
+    sizes = line.strip().strip("[]").strip().replace(' ', ',')
+
+    return {"<Sizes>" : sizes}
+
 def parse_fixed_bias_component(component, line, line_buffer):
     line = consume_token(component, line)
     line = consume_token("<Bias>", line)
@@ -433,7 +443,7 @@ def Main():
     tmpdir = tempfile.mkdtemp(dir=args.tmpdir) 
 
     # Convert nnet2 model to text and remove preconditioning
-    common_lib.run_kaldi_command("nnet-am-copy "
+    common_lib.execute_command("nnet-am-copy "
             "--remove-preconditioning=true --binary=false {0}/{1} {2}/{1}"
             .format(args.nnet2_dir, args.model, tmpdir))