feat!: Bump minimum Python version to 3.9

Also reverts old fixes specific to Python 3.6

docs/source/overview.rst

@@ -38,7 +38,7 @@ See also the more detailed list of :ref:`Features` below.
 Getting started
 ---------------
 
-Shaka Streamer requires `Python 3.6+`_.  Release versions of Shaka Streamer can
+Shaka Streamer requires `Python 3.9+`_.  Release versions of Shaka Streamer can
 be installed or upgraded through ``pip3`` with:
 
 .. code:: sh
@@ -167,9 +167,7 @@ the ``shaka-streamer`` script as an example of how to do this.  See also
 
 
 .. _config_files/: https://github.com/shaka-project/shaka-streamer/tree/main/config_files
-.. _issue #8: https://github.com/shaka-project/shaka-streamer/issues/8
 .. _issue #17: https://github.com/shaka-project/shaka-streamer/issues/17
-.. _issue #23: https://github.com/shaka-project/shaka-streamer/issues/23
-.. _Python 3.6+: https://www.python.org/downloads/
+.. _Python 3.9+: https://www.python.org/downloads/
 .. _Shaka Packager: https://github.com/shaka-project/shaka-packager
 .. _FFmpeg: https://ffmpeg.org/

setup.py

@@ -41,6 +41,6 @@
       'Operating System :: MacOS :: MacOS X',
       'Operating System :: Microsoft :: Windows',
   ],
-  # Python 3.6 tested in GitHub Actions CI
-  python_requires='>=3.6',
+  # Python 3.9+ tested in GitHub Actions CI
+  python_requires='>=3.9',
 )

streamer/configuration.py

@@ -246,7 +246,7 @@ def get_subtypes(
     # is something like "str" or "int" instead of "typing.List" or
     # "typing.Dict".
     if hasattr(typing, 'get_args'):
-      args = typing.get_args(type)  # type: ignore
+      args = typing.get_args(type)
     elif hasattr(type, '__args__'):
       # Before Python 3.8, you can use this undocumented attribute to get the
       # type parameters.  If this doesn't exist, you are probably dealing with a
@@ -256,9 +256,9 @@ def get_subtypes(
       args = ()
 
     underlying = Field.get_underlying_type(type)
-    if underlying in [dict, Dict]:
+    if underlying is dict:
       return cast(Tuple[Optional[Type], Optional[Type]], args)
-    if underlying in [list, List]:
+    if underlying is list:
       return (None, args[0])
     return (None, None)
 
@@ -272,11 +272,11 @@ def get_type_name_static(type: Optional[Type],
     if type is str:
       # Call it a string, not a "str".
       return 'string'
-    elif type in [list, List]:
+    elif type is list:
       # Mention the subtype.
       return 'list of {}'.format(
           Field.get_type_name_static(subtype, None, None))
-    elif type in [dict, Dict]:
+    elif type is dict:
       # Mention the subtype.
       return 'dictionary of {} to {}'.format(
           Field.get_type_name_static(keytype, None, None),
@@ -372,7 +372,7 @@ def _check_and_convert_type(self,
 
     # For lists, check the type of the value itself, then check the subtype of
     # the list items.
-    if field.type in [list, List]:
+    if field.type is list:
       if not isinstance(value, list):
         raise WrongType(self.__class__, key, field)
 
@@ -389,7 +389,7 @@ def _check_and_convert_type(self,
 
     # For dictionaries, check the type of the value itself, then check the
     # type of the dictionary keys, then the type of the dictionary values.
-    if field.type in [dict, Dict]:
+    if field.type is dict:
       if not isinstance(value, dict):
         raise WrongType(self.__class__, key, field)