Make Metadata.items more idiomatic in Python bindings

native_client/python/client.py

@@ -39,6 +39,7 @@ N_FEATURES = 26
 # Size of the context window used for producing timesteps in the input vector
 N_CONTEXT = 9
 
+
 def convert_samplerate(audio_path):
     sox_cmd = 'sox {} --type raw --bits 16 --channels 1 --rate 16000 --encoding signed-integer --endian little --compression 0.0 --no-dither - '.format(quote(audio_path))
     try:
@@ -50,11 +51,9 @@ def convert_samplerate(audio_path):
 
     return 16000, np.frombuffer(output, np.int16)
 
+
 def metadata_to_string(metadata):
-    retval = ''
-    for item in range(metadata.num_items):
-        retval += metadata.items[item].character
-    return retval
+    return ''.join(item.character for item in metadata.items)
 
 
 class VersionAction(argparse.Action):
@@ -65,6 +64,7 @@ class VersionAction(argparse.Action):
         printVersions()
         exit(0)
 
+
 def main():
     parser = argparse.ArgumentParser(description='Running DeepSpeech inference.')
     parser.add_argument('--model', required=True,

native_client/python/impl.i

@@ -33,17 +33,19 @@ import_array();
   %append_output(SWIG_NewPointerObj(%as_voidptr(*$1), $*1_descriptor, 0));
 }
 
-%extend struct MetadataItem {
-  MetadataItem* __getitem__(size_t i) {
-    return &$self[i];
-  }
-}
-
 %typemap(out) Metadata* {
   // owned, extended destructor needs to be called by SWIG
   %append_output(SWIG_NewPointerObj(%as_voidptr($1), $1_descriptor, SWIG_POINTER_OWN));
 }
 
+%typemap(out) MetadataItem* %{
+  $result = PyList_New(arg1->num_items);
+  for (int i = 0; i < arg1->num_items; ++i) {
+    PyObject* o = SWIG_NewPointerObj(SWIG_as_voidptr(&arg1->items[i]), SWIGTYPE_p_MetadataItem, 0);
+    PyList_SetItem($result, i, o);
+  }
+%}
+
 %extend struct Metadata {
   ~Metadata() {
     DS_FreeMetadata($self);

native_client/python/setup.cfg

@@ -1,6 +1,5 @@
 [build_ext]
 include-dirs=./
-swig-opts=-c++ -keyword
 build-lib=temp_build
 build-temp=temp_build
 

native_client/python/setup.py

@@ -7,6 +7,7 @@ import os
 import subprocess
 import sys
 
+def main():
     try:
         import numpy
         try:
@@ -47,6 +48,8 @@ def lib_dirs_split(a):
         if os.name == 'nt':
             return []
 
+        raise AssertionError('os.name == java not expected')
+
     def libs_split(a):
         if os.name == 'posix':
             return a.split('-l')[1:]
@@ -54,12 +57,14 @@ def libs_split(a):
         if os.name == 'nt':
             return a.split('.lib')[0:1]
 
-ds_ext = Extension('deepspeech._impl',
-         ['impl.i'],
+        raise AssertionError('os.name == java not expected')
+
+    ds_ext = Extension(name='deepspeech._impl',
+                       sources=['impl.i'],
                        include_dirs=[numpy_include, '../'],
                        library_dirs=list(map(lambda x: x.strip(), lib_dirs_split(os.getenv('MODEL_LDFLAGS', '')))),
-         libraries = list(map(lambda x: x.strip(), libs_split(os.getenv('MODEL_LIBS', ''))))
-         )
+                       libraries=list(map(lambda x: x.strip(), libs_split(os.getenv('MODEL_LIBS', '')))),
+                       swig_opts=['-c++', '-keyword', '-builtin'])
 
     setup(name=project_name,
           description='A library for running inference on a DeepSpeech model',
@@ -97,3 +102,6 @@ setup(name = project_name,
               'Topic :: Scientific/Engineering',
               'Topic :: Utilities',
           ])
+
+if __name__ == '__main__':
+    main()