1 files changed, 17 insertions, 0 deletions
diff --git a/pre_commit/prefix.py b/pre_commit/prefix.py
new file mode 100644
index 0000000..0e3ebbd
--- /dev/null
+++ b/pre_commit/prefix.py
@@ -0,0 +1,17 @@
+import os.path
+from typing import NamedTuple
+from typing import Tuple
+
+
+class Prefix(NamedTuple):
+    prefix_dir: str
+
+    def path(self, *parts: str) -> str:
+        return os.path.normpath(os.path.join(self.prefix_dir, *parts))
+
+    def exists(self, *parts: str) -> bool:
+        return os.path.exists(self.path(*parts))
+
+    def star(self, end: str) -> Tuple[str, ...]:
+        paths = os.listdir(self.prefix_dir)
+        return tuple(path for path in paths if path.endswith(end))