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

@@ -7,82 +7,87 @@ import os
 import subprocess
 import sys
 
-try:
+def main():
+    try:
         import numpy
         try:
             numpy_include = numpy.get_include()
         except AttributeError:
             numpy_include = numpy.get_numpy_include()
-except ImportError:
+    except ImportError:
         numpy_include = ''
         assert 'NUMPY_INCLUDE' in os.environ
 
-def read(fname):
+    def read(fname):
         return open(os.path.join(os.path.dirname(__file__), fname)).read()
 
-numpy_include = os.getenv('NUMPY_INCLUDE', numpy_include)
-numpy_min_ver = os.getenv('NUMPY_DEP_VERSION', '')
+    numpy_include = os.getenv('NUMPY_INCLUDE', numpy_include)
+    numpy_min_ver = os.getenv('NUMPY_DEP_VERSION', '')
 
-project_name = 'deepspeech'
-if '--project_name' in sys.argv:
+    project_name = 'deepspeech'
+    if '--project_name' in sys.argv:
         project_name_idx = sys.argv.index('--project_name')
         project_name = sys.argv[project_name_idx + 1]
         sys.argv.remove('--project_name')
         sys.argv.pop(project_name_idx)
 
-with open('../../VERSION', 'r') as ver:
+    with open('../../VERSION', 'r') as ver:
         project_version = ver.read().strip()
 
-class BuildExtFirst(build):
+    class BuildExtFirst(build):
         sub_commands = [('build_ext', build.has_ext_modules),
                         ('build_py', build.has_pure_modules),
                         ('build_clib', build.has_c_libraries),
                         ('build_scripts', build.has_scripts)]
 
-# Properly pass arguments for linking, setuptools will perform some checks
-def lib_dirs_split(a):
+    # Properly pass arguments for linking, setuptools will perform some checks
+    def lib_dirs_split(a):
         if os.name == 'posix':
             return a.split('-L')[1:]
 
         if os.name == 'nt':
             return []
 
-def libs_split(a):
+        raise AssertionError('os.name == java not expected')
+
+    def libs_split(a):
         if os.name == 'posix':
             return a.split('-l')[1:]
 
         if os.name == 'nt':
             return a.split('.lib')[0:1]
 
-ds_ext = Extension('deepspeech._impl',
-         ['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', ''))))
-         )
+        raise AssertionError('os.name == java not expected')
 
-setup(name = project_name,
-      description = 'A library for running inference on a DeepSpeech model',
-      long_description = read('../../README.md'),
-      long_description_content_type = 'text/markdown; charset=UTF-8',
-      author = 'Mozilla',
-      version = project_version,
-      package_dir = {'deepspeech': '.'},
-      cmdclass = {'build': BuildExtFirst},
-      license = 'MPL-2.0',
-      url = 'https://github.com/mozilla/DeepSpeech',
-      project_urls = {
+    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', '')))),
+                       swig_opts=['-c++', '-keyword', '-builtin'])
+
+    setup(name=project_name,
+          description='A library for running inference on a DeepSpeech model',
+          long_description=read('../../README.md'),
+          long_description_content_type='text/markdown; charset=UTF-8',
+          author='Mozilla',
+          version=project_version,
+          package_dir={'deepspeech': '.'},
+          cmdclass={'build': BuildExtFirst},
+          license='MPL-2.0',
+          url='https://github.com/mozilla/DeepSpeech',
+          project_urls={
               'Documentation': 'https://github.com/mozilla/DeepSpeech/tree/v{}#project-deepspeech'.format(project_version),
               'Tracker': 'https://github.com/mozilla/DeepSpeech/issues',
               'Repository': 'https://github.com/mozilla/DeepSpeech/tree/v{}'.format(project_version),
               'Discussions': 'https://discourse.mozilla.org/c/deep-speech',
           },
-      ext_modules = [ds_ext],
-      py_modules = ['deepspeech', 'deepspeech.client', 'deepspeech.impl'],
-      entry_points={'console_scripts':['deepspeech = deepspeech.client:main']},
-      install_requires = ['numpy%s' % numpy_min_ver],
-      include_package_data = True,
-      classifiers = [
+          ext_modules=[ds_ext],
+          py_modules=['deepspeech', 'deepspeech.client', 'deepspeech.impl'],
+          entry_points={'console_scripts':['deepspeech=deepspeech.client:main']},
+          install_requires=['numpy%s' % numpy_min_ver],
+          include_package_data=True,
+          classifiers=[
               'Development Status :: 3 - Alpha',
               'Environment :: Console',
               'Intended Audience :: Developers',
@@ -97,3 +102,6 @@ setup(name = project_name,
               'Topic :: Scientific/Engineering',
               'Topic :: Utilities',
           ])
+
+if __name__ == '__main__':
+    main()