Merge in latest from master

3 files changed, 22 insertions, 8 deletions

diff --git a/isort/__init__.py b/isort/__init__.py
index 3553b811..63034de6 100644
--- a/isort/__init__.py
+++ b/isort/__init__.py
@@ -22,4 +22,4 @@ OTHER DEALINGS IN THE SOFTWARE.
 from . import settings  # noqa: F401
 from .isort import SortImports  # noqa: F401
 
-__version__ = "4.3.8"
+__version__ = "4.3.9"
diff --git a/isort/finders.py b/isort/finders.py
index e21ef447..05abb585 100644
--- a/isort/finders.py
+++ b/isort/finders.py
@@ -34,6 +34,11 @@ try:
 except ImportError:
     Pipfile = None
 
+try:
+    from functools import lru_cache
+except ImportError:
+    from backports.functools_lru_cache import lru_cache
+
 
 KNOWN_SECTION_MAPPING = {
     'STDLIB': 'STANDARD_LIBRARY',
@@ -268,6 +273,13 @@ class RequirementsFinder(ReqsBaseFinder):
     def _get_files_from_dir(self, path: str) -> Iterator[str]:
         """Return paths to requirements files from passed dir.
         """
+        return RequirementsFinder._get_files_from_dir_cached(path)
+
+    @classmethod
+    @lru_cache(maxsize=16)
+    def _get_files_from_dir_cached(cls, path):
+        result = []
+
         for fname in os.listdir(path):
             if 'requirements' not in fname:
                 continue
@@ -276,16 +288,16 @@ class RequirementsFinder(ReqsBaseFinder):
             # *requirements*/*.{txt,in}
             if os.path.isdir(full_path):
                 for subfile_name in os.listdir(path):
-                    for ext in self.exts:
+                    for ext in cls.exts:
                         if subfile_name.endswith(ext):
-                            yield os.path.join(path, subfile_name)
+                            result.append(os.path.join(path, subfile_name))
                 continue
 
             # *requirements*.{txt,in}
             if os.path.isfile(full_path):
-                for ext in self.exts:
+                for ext in cls.exts:
                     if fname.endswith(ext):
-                        yield full_path
+                        result.append(full_path)
                         break
 
     def _get_names(self, path: str) -> Iterator[str]:
diff --git a/isort/settings.py b/isort/settings.py
index c1d17802..1fbd8cb6 100644
--- a/isort/settings.py
+++ b/isort/settings.py
@@ -28,7 +28,6 @@ import fnmatch
 import os
 import posixpath
 import re
-import stat
 import warnings
 from distutils.util import strtobool
 from functools import lru_cache
@@ -337,7 +336,10 @@ def should_skip(
     path: str = '/'
 ) -> bool:
     """Returns True if the file should be skipped based on the passed in settings."""
-    normalized_path = posixpath.join(path.replace('\\', '/'), filename)
+    os_path = os.path.join(path, filename)
+    normalized_path = os_path.replace('\\', '/')
+    if normalized_path[1:2] == ':':
+        normalized_path = normalized_path[2:]
 
     if config['safety_excludes'] and safety_exclude_re.search(normalized_path):
         return True
@@ -356,7 +358,7 @@ def should_skip(
         if fnmatch.fnmatch(filename, glob):
             return True
 
-    if stat.S_ISFIFO(os.stat(normalized_path).st_mode):
+    if not (os.path.isfile(os_path) or os.path.isdir(os_path) or os.path.islink(os_path)):
         return True
 
     return False