mkogg.py: Prefix imports with underscores for a clean namespace

diff --git a/posts/mkogg/mkogg.py b/posts/mkogg/mkogg.py
index a9bfdc6554539c5600383352bc3e9bbcc7397de6..581631ac3f5beafe5ff15558e1a8a67af9c12c44 100755 (executable)
--- a/posts/mkogg/mkogg.py
+++ b/posts/mkogg/mkogg.py
@@ -44,21 +44,21 @@ External packages required for full functionality:
 """
 
 from hashlib import sha256 as _hash
-import os
-import os.path
+import os as _os
 import re as _re
-import shutil
-from subprocess import Popen, PIPE
-from tempfile import mkstemp
+import shutil as _shutil
+import subprocess as _subprocess
+import tempfile as _tempfile
 
 try:
-    import mutagen.flac
-    import mutagen.id3
-    import mutagen.m4a
-    import mutagen.mp3
-    import mutagen.oggvorbis
-except ImportError, _mutagen_import_error:
-    mutagen = None
+    import mutagen as _mutagen
+    import mutagen.flac as _mutagen_flag
+    import mutagen.id3 as _mutagen_id3
+    import mutagen.m4a as _mutagen_m4a
+    import mutagen.mp3 as _mutagen_mp3
+    import mutagen.oggvorbis as _mutagen_oggvorbis
+except ImportError as _mutagen_import_error:
+    _mutagen = None
 
 
 __version__ = '0.4'
@@ -66,7 +66,9 @@ __version__ = '0.4'
 
 def invoke(args, stdin=None, expect=(0,)):
     print('  {}'.format(args))
-    p = Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE)
+    p = _subprocess.Popen(
+        args, stdin=_subprocess.PIPE, stdout=_subprocess.PIPE,
+        stderr=_subprocess.PIPE)
     stdout,stderr = p.communicate(stdin)
     status = p.wait()
     assert status in expect, 'invalid status {} from {}'.format(status, args)
@@ -129,10 +131,10 @@ class Converter (object):
         self._cache = self._read_cache()
         self._hash = hash
         self._ignore_function = ignore_function
-        f,self._tempfile = mkstemp(prefix='mkogg-')
+        f,self._tempfile = _tempfile.mkstemp(prefix='mkogg-')
 
     def cleanup(self):
-        os.remove(self._tempfile)
+        _os.remove(self._tempfile)
         self._save_cache()
 
     def _read_cache(self):
@@ -168,30 +170,30 @@ class Converter (object):
 
     def run(self):
         self._makedirs(self.target_dir)
-        for dirpath,dirnames,filenames in os.walk(self.source_dir):
+        for dirpath,dirnames,filenames in _os.walk(self.source_dir):
             for filename in filenames:
-                root,ext = os.path.splitext(filename)
+                root,ext = _os.path.splitext(filename)
                 ext = ext.lower()
                 if ext.startswith('.'):
                     ext = ext[1:]
                 if ext not in self._source_extensions:
                     print('skip', filename, ext)
                     continue
-                source_path = os.path.join(dirpath, filename)
+                source_path = _os.path.join(dirpath, filename)
                 if (self._ignore_function is not None and
                     self._ignore_function(source_path)):
                     continue
-                rel_path = os.path.relpath(dirpath, self.source_dir)
-                target_path = os.path.join(
+                rel_path = _os.path.relpath(dirpath, self.source_dir)
+                target_path = _os.path.join(
                     self.target_dir, rel_path,
                     '{}.{}'.format(root, self._target_extension))
-                target_dir = os.path.dirname(target_path)
+                target_dir = _os.path.dirname(target_path)
                 self._makedirs(target_dir)
                 self._convert(source_path, target_path, ext)
 
     def _makedirs(self, target_dir):
-        if not os.path.exists(target_dir):
-            os.makedirs(target_dir)
+        if not _os.path.exists(target_dir):
+            _os.makedirs(target_dir)
 
     def _convert(self, source, target, ext):
         if self._hash:
@@ -201,12 +203,12 @@ class Converter (object):
                 old_cache_value == self._cache_value(target)):
                 print('already cached {} to {}'.format(source, target))
                 return
-        elif os.path.exists(target):
+        elif _os.path.exists(target):
             print('target {} already exists'.format(target))
             return
         print('convert {} to {}'.format(source, target))
         if ext == self._target_extension:
-            shutil.copy(source, target)
+            _shutil.copy(source, target)
             return
         try:
             convert = getattr(self, 'convert_{}_to_{}'.format(
@@ -295,7 +297,7 @@ class Converter (object):
         if 'tracktotal' in metadata:
             value = []
             for i,v in enumerate(metadata['tracknumber']):
-                value.append(u'{}/{}'.format(
+                value.append('{}/{}'.format(
                         v, metadata['tracktotal'][i]))
         else:
             value = metadata['tracknumber']
@@ -342,14 +344,14 @@ class Converter (object):
         self.convert_flac_to_ogg(source, target)
 
     def get_flac_metadata(self, source):
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error
-        return mutagen.flac.FLAC(source)
+        return _mutagen_flac.FLAC(source)
 
     def get_m4a_metadata(self, source):
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error
-        m4a = mutagen.m4a.M4A(source)
+        m4a = _mutagen_m4a.M4A(source)
         metadata = {}
         for key,value in m4a.items():
             try:
@@ -370,9 +372,9 @@ class Converter (object):
         return metadata
 
     def get_mp3_metadata(self, source):
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error
-        mp3 = mutagen.mp3.MP3(source)
+        mp3 = _mutagen_mp3.MP3(source)
         metadata = {}
         for key,value in mp3.items():
             try:
@@ -382,34 +384,34 @@ class Converter (object):
             v = value.text
             if vorbis_key == 'tracknumber':
                 for i,v_entry in enumerate(v):
-                    if u'/' in v_entry:
-                        tracknumber,tracktotal = v_entry.split(u'/', 1)
+                    if '/' in v_entry:
+                        tracknumber,tracktotal = v_entry.split('/', 1)
                         v[i] = tracknumber
                         metadata['tracktotal'] = ['tracktotal']
             metadata[vorbis_key] = v
         return metadata
 
     def get_ogg_metadata(self, source):
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error        
-        return mutagen.oggvorbis.OggVorbis(source)
+        return _mutagen_oggvorbis.OggVorbis(source)
 
     def get_wav_metadata(self, source):
         return {}
 
     def set_flac_metadata(self, target, metadata):
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error
-        flac = mutagen.flac.FLAC(target)
+        flac = _mutagen_flac.FLAC(target)
         self._set_vorbis_comments(flac, metadata)
         flac.save()
 
     def set_mp3_metadata(self, target, metadata):
         vorbis_keys_to_id3 = dict(
             (v,k) for k,v in self.id3_to_vorbis_keys.items())
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error
-        mp3 = mutagen.mp3.MP3(target)
+        mp3 = _mutagen_mp3.MP3(target)
         if mp3.tags is not None:
             mp3.tags.delete()
         handled_trck = False
@@ -430,7 +432,7 @@ class Converter (object):
                 frame_name = vorbis_keys_to_id3[key].upper()
             except KeyError:
                 continue
-            frame = getattr(mutagen.id3, frame_name)
+            frame = getattr(_mutagen_id3, frame_name)
             id3_encoding = self._guess_id3_encoding(value)
             max_encoding = max(max_encoding, id3_encoding)
             mp3[frame_name] = frame(encoding=id3_encoding, text=value)
@@ -443,9 +445,9 @@ class Converter (object):
         mp3.save(v1=v1)
 
     def set_ogg_metadata(self, target, metadata):
-        if mutagen is None:
+        if _mutagen is None:
             raise _mutagen_import_error
-        ogg = mutagen.oggvorbis.OggVorbis(target)
+        ogg = _mutagen_oggvorbis.OggVorbis(target)
         self._set_vorbis_comments(ogg, metadata)
         ogg.save()