matplotlib · timhoffm · Jul 9, 2018 · Jun 7, 2018 · Jun 7, 2018 · Jun 24, 2018
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -216,13 +216,6 @@ def compare_versions(a, b):
     sys.argv = ['modpython']
 
 
-def _is_writable_dir(p):
-    """
-    p is a string pointing to a putative writable dir -- return True p
-    is such a string, else False
-    """
-    return os.access(p, os.W_OK) and os.path.isdir(p)
-
 _verbose_msg = """\
 matplotlib.verbose is deprecated;
 Command line argument --verbose-LEVEL is deprecated.
@@ -393,27 +386,34 @@ def ge(self, level):
     verbose = Verbose()
 
 
-def _wrap(fmt, func, level=logging.DEBUG, always=True):
+def _logged_cached(fmt, func=None):
     """
-    return a callable function that wraps func and reports its
-    output through logger
+    Decorator that logs a function's return value, and memoizes that value.
 
-    if always is True, the report will occur on every function
-    call; otherwise only on the first time the function is called
-    """
-    assert callable(func)
+    After ::
 
-    def wrapper(*args, **kwargs):
-        ret = func(*args, **kwargs)
+        @_logged_cached(fmt)
+        def func(): ...
 
-        if (always or not wrapper._spoke):
-            _log.log(level, fmt % ret)
-            spoke = True
-            if not wrapper._spoke:
-                wrapper._spoke = spoke
+    the first call to *func* will log its return value at the DEBUG level using
+    %-format string *fmt*, and memoize it; later calls to *func* will directly
+    return that value.
+    """
+    if func is None:  # Return the actual decorator.
+        return functools.partial(_logged_cached, fmt)
+
+    called = False
+    ret = None
+
+    @functools.wraps(func)
+    def wrapper():
+        nonlocal called, ret
+        if not called:
+            ret = func()
+            called = True
+            _log.debug(fmt, ret)
         return ret
-    wrapper._spoke = False
-    wrapper.__doc__ = func.__doc__
+
     return wrapper
 
 
@@ -551,49 +551,39 @@ def checkdep_usetex(s):
     return flag
 
 
-def _get_home():
-    """Find user's home directory if possible.
-    Otherwise, returns None.
+@_logged_cached('$HOME=%s')
+def get_home():
+    """
+    Return the user's home directory.
 
-    :see:
-        http://mail.python.org/pipermail/python-list/2005-February/325395.html
+    If the user's home directory cannot be found, return None.
     """
-    path = os.path.expanduser("~")
-    if os.path.isdir(path):
-        return path
-    for evar in ('HOME', 'USERPROFILE', 'TMP'):
-        path = os.environ.get(evar)
-        if path is not None and os.path.isdir(path):
-            return path
-    return None
+    try:
+        return str(Path.home())
+    except Exception:
+        return None
 
 
 def _create_tmp_config_dir():
     """
-    If the config directory can not be created, create a temporary
-    directory.
+    If the config directory can not be created, create a temporary directory.
     """
     configdir = os.environ['MPLCONFIGDIR'] = (
         tempfile.mkdtemp(prefix='matplotlib-'))
     atexit.register(shutil.rmtree, configdir)
     return configdir
 
 
-get_home = _wrap('$HOME=%s', _get_home, always=False)
-
-
 def _get_xdg_config_dir():
     """
     Returns the XDG configuration directory, according to the `XDG
     base directory spec
     <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_.
     """
-    path = os.environ.get('XDG_CONFIG_HOME')
-    if path is None:
-        path = get_home()
-        if path is not None:
-            path = os.path.join(path, '.config')
-    return path
+    return (os.environ.get('XDG_CONFIG_HOME')
+            or (str(Path(get_home(), ".config"))
+                if get_home()
+                else None))
 
 
 def _get_xdg_cache_dir():
@@ -602,60 +592,46 @@ def _get_xdg_cache_dir():
     base directory spec
     <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_.
     """
-    path = os.environ.get('XDG_CACHE_HOME')
-    if path is None:
-        path = get_home()
-        if path is not None:
-            path = os.path.join(path, '.cache')
-    return path
+    return (os.environ.get('XDG_CACHE_HOME')
+            or (str(Path(get_home(), ".cache"))
+                if get_home()
+                else None))
 
 
 def _get_config_or_cache_dir(xdg_base):
     configdir = os.environ.get('MPLCONFIGDIR')
-    if configdir is not None:
-        configdir = os.path.abspath(configdir)
-        Path(configdir).mkdir(parents=True, exist_ok=True)
-        if not _is_writable_dir(configdir):
-            return _create_tmp_config_dir()
-        return configdir
-
-    p = None
-    h = get_home()
-    if h is not None:
-        p = os.path.join(h, '.matplotlib')
-    if sys.platform.startswith(('linux', 'freebsd')):
-        p = None
-        if xdg_base is not None:
-            p = os.path.join(xdg_base, 'matplotlib')
-
-    if p is not None:
-        if os.path.exists(p):
-            if _is_writable_dir(p):
-                return p
+    if configdir:
+        configdir = Path(configdir).resolve()
+    elif sys.platform.startswith(('linux', 'freebsd')) and xdg_base:
+        configdir = Path(xdg_base, "matplotlib")
+    elif get_home():
+        configdir = Path(get_home(), ".matplotlib")
+    else:
+        configdir = None
+
+    if configdir:
+        try:
+            configdir.mkdir(parents=True, exist_ok=True)
+        except OSError:
+            pass
         else:
-            try:
-                Path(p).mkdir(parents=True, exist_ok=True)
-            except OSError:
-                pass
-            else:
-                return p
+            if os.access(str(configdir), os.W_OK) and configdir.is_dir():
+                return str(configdir)
 
     return _create_tmp_config_dir()
 
 
-def _get_configdir():
+@_logged_cached('CONFIGDIR=%s')
+def get_configdir():
     """
     Return the string representing the configuration directory.
 
     The directory is chosen as follows:
 
     1. If the MPLCONFIGDIR environment variable is supplied, choose that.
-
     2a. On Linux, follow the XDG specification and look first in
         `$XDG_CONFIG_HOME`, if defined, or `$HOME/.config`.
-
     2b. On other platforms, choose `$HOME/.matplotlib`.
-
     3. If the chosen directory exists and is writable, use that as the
        configuration directory.
     4. If possible, create a temporary directory, and use it as the
@@ -664,10 +640,9 @@ def _get_configdir():
     """
     return _get_config_or_cache_dir(_get_xdg_config_dir())
 
-get_configdir = _wrap('CONFIGDIR=%s', _get_configdir, always=False)
 
-
-def _get_cachedir():
+@_logged_cached('CACHEDIR=%s')
+def get_cachedir():
     """
     Return the location of the cache directory.
 
@@ -676,8 +651,6 @@ def _get_cachedir():
     """
     return _get_config_or_cache_dir(_get_xdg_cache_dir())
 
-get_cachedir = _wrap('CACHEDIR=%s', _get_cachedir, always=False)
-
 
 def _decode_filesystem_path(path):
     if not isinstance(path, str):
@@ -729,14 +702,12 @@ def _get_data_path():
     raise RuntimeError('Could not find the matplotlib data files')
 
 
-def _get_data_path_cached():
+@_logged_cached('matplotlib data path: %s')
+def get_data_path():
     if defaultParams['datapath'][0] is None:
         defaultParams['datapath'][0] = _get_data_path()
     return defaultParams['datapath'][0]
 
-get_data_path = _wrap('matplotlib data path %s', _get_data_path_cached,
-                      always=False)
-
 
 def get_py2exe_datafiles():
     data_path = Path(get_data_path())
@@ -787,7 +758,7 @@ def gen_candidates():
         else:
             yield matplotlibrc
             yield os.path.join(matplotlibrc, 'matplotlibrc')
-        yield os.path.join(_get_configdir(), 'matplotlibrc')
+        yield os.path.join(get_configdir(), 'matplotlibrc')
         yield os.path.join(get_data_path(), 'matplotlibrc')
 
     for fname in gen_candidates():

diff --git a/lib/matplotlib/cbook/__init__.py b/lib/matplotlib/cbook/__init__.py
@@ -1984,7 +1984,7 @@ class so far, an alias named ``get_alias`` will be defined; the same will
     can be used by `~.normalize_kwargs` (which assumes that higher priority
     aliases come last).
     """
-    if cls is None:
+    if cls is None:  # Return the actual class decorator.
         return functools.partial(_define_aliases, alias_d)
 
     def make_alias(name):  # Enforce a closure over *name*.

diff --git a/lib/matplotlib/style/core.py b/lib/matplotlib/style/core.py
@@ -25,7 +25,7 @@
 
 BASE_LIBRARY_PATH = os.path.join(mpl.get_data_path(), 'stylelib')
 # Users may want multiple library paths, so store a list of paths.
-USER_LIBRARY_PATHS = [os.path.join(mpl._get_configdir(), 'stylelib')]
+USER_LIBRARY_PATHS = [os.path.join(mpl.get_configdir(), 'stylelib')]
 STYLE_EXTENSION = 'mplstyle'
 STYLE_FILE_PATTERN = re.compile(r'([\S]+).%s$' % STYLE_EXTENSION)
 

diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -18,9 +18,7 @@
 
 import matplotlib
 from matplotlib.testing.exceptions import ImageComparisonFailure
-from matplotlib import _png
-from matplotlib import _get_cachedir
-from matplotlib import cbook
+from matplotlib import _png, cbook
 
 __all__ = ['compare_float', 'compare_images', 'comparable_formats']
 
@@ -79,7 +77,7 @@ def compare_float(expected, actual, relTol=None, absTol=None):
 
 
 def get_cache_dir():
-    cachedir = _get_cachedir()
+    cachedir = matplotlib.get_cachedir()
     if cachedir is None:
         raise RuntimeError('Could not find a suitable configuration directory')
     cache_dir = os.path.join(cachedir, 'test_cache')
@@ -293,15 +291,12 @@ def comparable_formats():
 
 def convert(filename, cache):
     """
-    Convert the named file into a png file.  Returns the name of the
-    created file.
+    Convert the named file to png; return the name of the created file.
 
     If *cache* is True, the result of the conversion is cached in
-    `matplotlib._get_cachedir() + '/test_cache/'`.  The caching is based
-    on a hash of the exact contents of the input file.  The is no limit
-    on the size of the cache, so it may need to be manually cleared
-    periodically.
-
+    `matplotlib.get_cachedir() + '/test_cache/'`.  The caching is based on a
+    hash of the exact contents of the input file.  There is no limit on the
+    size of the cache, so it may need to be manually cleared periodically.
     """
     base, extension = filename.rsplit('.', 1)
     if extension not in converter: