generators: Teach Generator.get_files to handle non-directory input

This makes it easier for StaticGenerator to walk FILES_TO_COPY, where
the input may be a directory or a bare filename.

Non-traversable file types (e.g. everything but directories and
symlinks to directories) are not checked against the exclude list.
The user-level effect of this is that explicit entries in STATIC_PATHS
or FILES_TO_COPY will override a hypothetical STATIC_EXCLUDES setting,
which seems like a reasonable approach.

I also removed the Python 2.5 compatibility check for `followlinks` in
os.walk, since Pelican is now Python >=2.7.

pelican/generators.py

@@ -84,6 +84,21 @@ class Generator(object):
                          % (name, self._templates_path)))
         return self._templates[name]
 
+    def _include_path(self, path, extensions=None):
+        """Inclusion logic for .get_files(), returns True/False
+
+        :param path: the path which might be including
+        :param extensions: the list of allowed extensions (if False, all
+            extensions are allowed)
+        """
+        if extensions is None:
+            extensions = self.markup
+        basename = os.path.basename(path)
+        if extensions is False or \
+                (True in [basename.endswith(ext) for ext in extensions]):
+            return True
+        return False
+
     def get_files(self, path, exclude=[], extensions=None):
         """Return a list of files to use, based on rules
 
@@ -92,24 +107,19 @@ class Generator(object):
         :param extensions: the list of allowed extensions (if False, all
             extensions are allowed)
         """
-        if extensions is None:
-            extensions = self.markup
-
         files = []
 
-        try:
-            iter = os.walk(path, followlinks=True)
-        except TypeError:  # python 2.5 does not support followlinks
-            iter = os.walk(path)
-
-        for root, dirs, temp_files in iter:
+        if os.path.isdir(path):
+            for root, dirs, temp_files in os.walk(path, followlinks=True):
                 for e in exclude:
                     if e in dirs:
                         dirs.remove(e)
                 for f in temp_files:
-                if extensions is False or \
-                        (True in [f.endswith(ext) for ext in extensions]):
-                    files.append(os.sep.join((root, f)))
+                    fp = os.path.join(root, f)
+                    if self._include_path(fp, extensions):
+                        files.append(fp)
+        elif os.path.exists(path) and self._include_path(path, extensions):
+            files.append(path)  # can't walk non-directories
         return files
 
     def add_source_path(self, content):