Removed importlib_resources dependency when using python < 3.9

bluesky/pathfinder.py

@@ -1,5 +1,4 @@
 ''' BlueSky resource access '''
-import sys
 import shutil
 import itertools
 from pathlib import Path
@@ -10,8 +9,25 @@
     from importlib.readers import MultiplexedPath
 except ImportError:
     # Python < 3.9 only provides deprecated resources API
-    from importlib_resources import files
-    from importlib_resources.readers import MultiplexedPath
+    from importlib.resources import path
+    def files(package):
+        res = '.'
+        if '.' in package:
+            package, res = package.split('.', 1)
+        return path(package, res)
+
+    class MultiplexedPath:
+        def __init__(self, *paths) -> None:
+            self._paths = list(map(Path, paths))
+        def iterdir(self):
+            visited = []
+            for path in self._paths:
+                for file in path.iterdir():
+                    if file.name in visited:
+                        continue
+                    visited.append(file.name)
+                    yield file
+
 
 
 class ResourcePath(MultiplexedPath):

setup.py

@@ -19,10 +19,6 @@ def get_numpy_include():
 with open(os.path.join(here, 'requirements.txt'), encoding='utf-8') as f:
     install_requires = f.readlines()
 
-# If Python version < 3.9, add importlib_resources requirement
-if sys.version_info.major == 3 and sys.version_info.minor < 9:
-    install_requires.append('importlib_resources')
-
 # get extra requirements from setup.cfg
 parser = configparser.ConfigParser()
 parser.read('%s/setup.cfg' % here)