Text twiddles

wavinfo/__main__.py

@@ -60,7 +60,8 @@ def main():
 
                 json.dump(ret_dict, cls=MyJSONEncoder, fp=sys.stdout, indent=2)
         except MissingDataError as e:
-            print("MissingDataError: Missing metadata (%s) in file %s" % (e, arg), file=sys.stderr)
+            print("MissingDataError: Missing metadata (%s) in file %s" % \
+                    (e, arg), file=sys.stderr)
             continue
         except Exception as e:
             raise e

wavinfo/rf64_parser.py

@@ -22,7 +22,8 @@ def parse_rf64(stream, signature = b'RF64') -> RF64Context:
     assert(len(ds64_data) >= ds64_fields_size)
 
     riff_size, data_size, sample_count, length_lookup_table = struct.unpack(
-        ds64_field_spec, ds64_data[0:ds64_fields_size])
+        ds64_field_spec, ds64_data[0:ds64_fields_size]
+        )
 
     bigchunk_table = {}
     chunksize64format = "<4sL"

wavinfo/riff_parser.py

@@ -1,7 +1,8 @@
 
+from optparse import Option
 import struct
-from collections import namedtuple
-from .rf64_parser import parse_rf64
+from .rf64_parser import parse_rf64, RF64Context
+from typing import NamedTuple, Union, List, Optional
 
 
 class WavInfoEOFError(EOFError):
@@ -10,11 +11,17 @@ class WavInfoEOFError(EOFError):
         self.chunk_start = chunk_start
 
 
-class ListChunkDescriptor(namedtuple('ListChunkDescriptor', 'signature children')):
-    pass
+class ListChunkDescriptor(NamedTuple):
+    signature: bytes 
+    children: List[Union['ChunkDescriptor', 'ListChunkDescriptor']]
 
 
-class ChunkDescriptor(namedtuple('ChunkDescriptor', 'ident start length rf64_context')):
+class ChunkDescriptor(NamedTuple):
+    ident: bytes
+    start: int 
+    length: int 
+    rf64_context: Optional[RF64Context]
+
     def read_data(self, from_stream) -> bytes:
         from_stream.seek(self.start)
         return from_stream.read(self.length)
@@ -64,5 +71,7 @@ def parse_chunk(stream, rf64_context=None):
     else:
         data_start = stream.tell()
         stream.seek(displacement, 1)
-        return ChunkDescriptor(ident=ident, start=data_start, length=data_size,
+        return ChunkDescriptor(ident=ident, 
+                               start=data_start, 
+                               length=data_size,
                                rf64_context=rf64_context)

wavinfo/wave_adm_reader.py

@@ -5,7 +5,7 @@ ADM Reader
 from struct import unpack, unpack_from, calcsize
 from io import BytesIO
 from collections import namedtuple
-from typing import Iterable, Tuple
+from typing import Optional
 
 from lxml import etree as ET
 
@@ -26,24 +26,20 @@ class WavADMReader:
 
         _, uid_count = unpack(header_fmt, chna_data[0:4])
 
-        #: A list of :class:`ChannelEntry` objects parsed from the
-        #: `chna` metadata chunk.
-        #:
-        #: .. note::
-        #:    In-file, the `chna` track indexes start at 1. However, this interface
-        #:    numbers the first track 0, in order to maintain consistency with other
-        #:    libraries.
         self.channel_uids = []
 
         offset = calcsize(header_fmt)
         for _ in range(uid_count):
 
-            track_index, uid, track_ref, pack_ref = unpack_from(uid_fmt, chna_data, offset)
+            track_index, uid, track_ref, pack_ref = unpack_from(uid_fmt, 
+                                                                chna_data, 
+                                                                offset)
 
             # these values are either ascii or all null
 
             self.channel_uids.append(ChannelEntry(track_index - 1,
-                uid.decode('ascii') , track_ref.decode('ascii'), pack_ref.decode('ascii')))
+                uid.decode('ascii') , track_ref.decode('ascii'), 
+                                                  pack_ref.decode('ascii')))
 
             offset += calcsize(uid_fmt)
 
@@ -53,7 +49,8 @@ class WavADMReader:
 
     def programme(self) -> dict:
         """
-        Read the ADM `audioProgramme` data structure and some of its reference properties. 
+        Read the ADM `audioProgramme` data structure and some of its reference 
+        properties. 
         """
         ret_dict = dict()
 
@@ -68,17 +65,21 @@ class WavADMReader:
         ret_dict['programme_end'] = program.get("end")
         ret_dict['contents'] = []
 
-        for content_ref in program.findall("audioContentIDRef", namespaces=nsmap):
+        for content_ref in program.findall("audioContentIDRef", 
+                                           namespaces=nsmap):
             content_dict = dict()
             content_dict['content_id'] = cid = content_ref.text
-            content = afext.find("audioContent[@audioContentID='%s']" % cid, namespaces=nsmap)
+            content = afext.find("audioContent[@audioContentID='%s']" % cid, 
+                                 namespaces=nsmap)
             content_dict['content_name'] = content.get("audioContentName")
             content_dict['objects'] = []
 
-            for object_ref in content.findall("audioObjectIDRef", namespaces=nsmap):
+            for object_ref in content.findall("audioObjectIDRef", 
+                                              namespaces=nsmap):
                 object_dict = dict()
                 object_dict['object_id'] = oid = object_ref.text
-                object = afext.find("audioObject[@audioObjectID='%s']" % oid, namespaces=nsmap)
+                object = afext.find("audioObject[@audioObjectID='%s']" % oid, 
+                                    namespaces=nsmap)
                 pack = object.find("audioPackFormatIDRef", namespaces=nsmap)
                 object_dict['object_name'] = object.get("audioObjectName")
                 object_dict['object_start'] = object.get("start")
@@ -95,15 +96,17 @@ class WavADMReader:
 
         return ret_dict
 
-    def track_info(self, index) -> dict:
+    def track_info(self, index) -> Optional[dict]:
         """
         Information about a track in the WAV file.
 
         :param index: index of audio track (indexed from zero) 
-        :returns: a dictionary with *content_name*, *content_id*, *object_name*, *object_id*, 
+        :returns: a dictionary with *content_name*, *content_id*, 
+            *object_name*, *object_id*, 
             *pack_format_name*, *pack_type*, *channel_format_name*
         """
-        channel_info = next((x for x in self.channel_uids if x.track_index == index), None)
+        channel_info = next((x for x in self.channel_uids \
+                if x.track_index == index), None)
         
         if channel_info is None:
             return None
@@ -114,36 +117,50 @@ class WavADMReader:
 
         afext = self.axml.find(".//audioFormatExtended", namespaces=nsmap)
 
-        trackformat_elem = afext.find("audioTrackFormat[@audioTrackFormatID='%s']" % channel_info.track_ref, 
+        trackformat_elem = afext.find(
+                "audioTrackFormat[@audioTrackFormatID='%s']" \
+                        % channel_info.track_ref, 
             namespaces=nsmap)
 
         stream_id = trackformat_elem[0].text
 
-        channelformatref_elem = afext.find("audioStreamFormat[@audioStreamFormatID='%s']/audioChannelFormatIDRef" % stream_id, 
+        channelformatref_elem = afext.find(
+                ("audioStreamFormat[@audioStreamFormatID='%s']"
+                "/audioChannelFormatIDRef") % stream_id, 
             namespaces=nsmap)
         channelformat_id = channelformatref_elem.text
 
-        packformatref_elem = afext.find("audioStreamFormat[@audioStreamFormatID='%s']/audioPackFormatIDRef" % stream_id, 
+        packformatref_elem = afext\
+                .find(("audioStreamFormat[@audioStreamFormatID='%s']"
+                                        "/audioPackFormatIDRef") % stream_id, 
             namespaces=nsmap)
         packformat_id = packformatref_elem.text
 
-        channelformat_elem = afext.find("audioChannelFormat[@audioChannelFormatID='%s']" % channelformat_id, 
+        channelformat_elem = afext\
+                .find("audioChannelFormat[@audioChannelFormatID='%s']" \
+                % channelformat_id, 
             namespaces=nsmap)
-        ret_dict['channel_format_name'] = channelformat_elem.get("audioChannelFormatName")
+        ret_dict['channel_format_name'] = channelformat_elem.get(
+                "audioChannelFormatName")
 
-        packformat_elem = afext.find("audioPackFormat[@audioPackFormatID='%s']" % packformat_id, 
+        packformat_elem = afext.find(
+                "audioPackFormat[@audioPackFormatID='%s']" % packformat_id, 
             namespaces=nsmap)
-        ret_dict['pack_type'] = packformat_elem.get("typeDefinition")
-        ret_dict['pack_format_name'] = packformat_elem.get("audioPackFormatName")
+        ret_dict['pack_type'] = packformat_elem.get(
+                "typeDefinition")
+        ret_dict['pack_format_name'] = packformat_elem.get(
+                "audioPackFormatName")
 
-        object_elem = afext.find("audioObject[audioPackFormatIDRef = '%s']" % packformat_id, 
+        object_elem = afext.find("audioObject[audioPackFormatIDRef = '%s']" \
+                % packformat_id, 
             namespaces=nsmap)
 
         ret_dict['audio_object_name'] = object_elem.get("audioObjectName")
         object_id = object_elem.get("audioObjectID")
         ret_dict['object_id'] = object_id
 
-        content_elem = afext.find("audioContent/[audioObjectIDRef = '%s']" % object_id, 
+        content_elem = afext.find("audioContent/[audioObjectIDRef = '%s']" \
+                % object_id, 
             namespaces=nsmap)
 
         ret_dict['content_name'] = content_elem.get("audioContentName")
@@ -161,5 +178,6 @@ class WavADMReader:
             rd.update(self.track_info(channel_uid_rec.track_index))
             return rd
 
-        return dict(channel_entries=list(map(lambda z: make_entry(z), self.channel_uids)),
-            programme=self.programme())
+        return dict(channel_entries=list(map(lambda z: make_entry(z), 
+                                             self.channel_uids)),
+            programme=self.programme())