drop Python 3.6: docs, a few safe simplifications

beets/autotag/hooks.py

@@ -28,12 +28,6 @@ from unidecode import unidecode
 
 log = logging.getLogger('beets')
 
-# The name of the type for patterns in re changed in Python 3.7.
-try:
-    Pattern = re._pattern_type
-except AttributeError:
-    Pattern = re.Pattern
-
 
 # Classes used to represent candidate options.
 class AttrDict(dict):
@@ -449,7 +443,7 @@ class Distance:
         be a compiled regular expression, in which case it will be
         matched against `value2`.
         """
-        if isinstance(value1, Pattern):
+        if isinstance(value1, re.Pattern):
             return bool(value1.match(value2))
         return value1 == value2
 

beets/util/__init__.py

@@ -868,10 +868,7 @@ def command_output(cmd, shell=False):
     """
     cmd = convert_command_args(cmd)
 
-    try:  # python >= 3.3
-        devnull = subprocess.DEVNULL
-    except AttributeError:
-        devnull = open(os.devnull, 'r+b')
+    devnull = subprocess.DEVNULL
 
     proc = subprocess.Popen(
         cmd,
@@ -1054,8 +1051,7 @@ def asciify_path(path, sep_replace):
 def par_map(transform, items):
     """Apply the function `transform` to all the elements in the
     iterable `items`, like `map(transform, items)` but with no return
-    value. The map *might* happen in parallel: it's parallel on Python 3
-    and sequential on Python 2.
+    value.
 
     The parallelism uses threads (not processes), so this is only useful
     for IO-bound `transform`s.

beets/util/functemplate.py

@@ -530,18 +530,7 @@ def _parse(template):
     return Expression(parts)
 
 
-def cached(func):
-    """Like the `functools.lru_cache` decorator, but works (as a no-op)
-    on Python < 3.2.
-    """
-    if hasattr(functools, 'lru_cache'):
-        return functools.lru_cache(maxsize=128)(func)
-    else:
-        # Do nothing when lru_cache is not available.
-        return func
-
-
-@cached
+@functools.lru_cache(maxsize=128)
 def template(fmt):
     return Template(fmt)
 

beetsplug/smartplaylist.py

@@ -24,12 +24,7 @@ from beets.library import Item, Album, parse_query_string
 from beets.dbcore import OrQuery
 from beets.dbcore.query import MultipleSort, ParsingError
 import os
-
-try:
-    from urllib.request import pathname2url
-except ImportError:
-    # python2 is a bit different
-    from urllib import pathname2url
+from urllib.request import pathname2url
 
 
 class SmartPlaylistPlugin(BeetsPlugin):

docs/changelog.rst

@@ -6,6 +6,9 @@ Changelog
 
 Changelog goes here!
 
+With this release, beets now requires Python 3.7 or later (it removes support
+for Python 3.6).
+
 New features:
 
 * We now import the remixer field from Musicbrainz into the library.
@@ -125,6 +128,7 @@ Bug fixes:
 
 For packagers:
 
+* As noted above, the minimum Python version is now 3.7.
 * We fixed a version for the dependency on the `Confuse`_ library.
   :bug:`4167`
 * The minimum required version of :pypi:`mediafile` is now 0.9.0.

docs/guides/main.rst

@@ -10,7 +10,7 @@ Installing
 ----------
 
 You will need Python.
-Beets works on Python 3.6 or later.
+Beets works on Python 3.7 or later.
 
 * **macOS** 11 (Big Sur) includes Python 3.8 out of the box.
   You can opt for a more recent Python installing it via `Homebrew`_
@@ -94,7 +94,7 @@ Installing on Windows
 Installing beets on Windows can be tricky. Following these steps might help you
 get it right:
 
-1. If you don't have it, `install Python`_ (you want at least Python 3.6). The
+1. If you don't have it, `install Python`_ (you want at least Python 3.7). The
    installer should give you the option to "add Python to PATH." Check this
    box. If you do that, you can skip the next step.
 
@@ -105,7 +105,7 @@ get it right:
    should open the "System Properties" screen, then select the "Advanced" tab, 
    then hit the "Environmental Variables..." button, and then look for the PATH 
    variable in the table. Add the following to the end of the variable's value: 
-   ``;C:\Python36;C:\Python36\Scripts``. You may need to adjust these paths to 
+   ``;C:\Python37;C:\Python37\Scripts``. You may need to adjust these paths to 
    point to your Python installation.
 
 3. Now install beets by running: ``pip install beets``

setup.py

@@ -166,10 +166,10 @@ setup(
         'Environment :: Web Environment',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
         'Programming Language :: Python :: Implementation :: CPython',
     ],
 )