diff --git a/git-importer.py b/git-importer.py
index f276bf3..eabadbf 100755
--- a/git-importer.py
+++ b/git-importer.py
@@ -91,7 +91,7 @@ def main():
         return
 
     if not args.repodir:
-        args.repodir = pathlib.Path("repos/" + args.package)
+        args.repodir = pathlib.Path("repos") / args.package
 
     importer = Importer(URL_OBS, "openSUSE:Factory", args.package)
     importer.import_into_db()
diff --git a/lib/abstract_walker.py b/lib/abstract_walker.py
index e1370ba..2526908 100644
--- a/lib/abstract_walker.py
+++ b/lib/abstract_walker.py
@@ -1,6 +1,10 @@
-class AbstractWalker:
+from abc import ABC, abstractmethod
+
+
+class AbstractWalker(ABC):
     """Just a duck type, most likely not needed by python, but I
     find interface classes preferable (java school)"""
 
+    @abstractmethod
     def call(self, node, is_source):
         pass
diff --git a/lib/db_revision.py b/lib/db_revision.py
index cf2e4aa..da37166 100644
--- a/lib/db_revision.py
+++ b/lib/db_revision.py
@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import logging
 from hashlib import md5
+from pathlib import PurePath
 from typing import Optional
 
 from lib.db import DB
@@ -223,11 +224,11 @@ class DBRevision:
         for entry in self.files_list(db):
             if old_files.get(entry["name"]) != f"{entry['md5']}-{entry['size']}":
                 logging.debug(f"Download {entry['name']}")
-                to_download.append((entry["name"], entry["md5"]))
+                to_download.append((PurePath(entry["name"]), entry["md5"]))
             old_files.pop(entry["name"], None)
         for entry in old_files.keys():
             logging.debug(f"Delete {entry}")
-            to_delete.append(entry)
+            to_delete.append(PurePath(entry))
         return to_download, to_delete
 
     @staticmethod
diff --git a/lib/flat_walker.py b/lib/flat_walker.py
index 7b2df52..7176da6 100644
--- a/lib/flat_walker.py
+++ b/lib/flat_walker.py
@@ -9,12 +9,8 @@ class FlatNode:
         self.parent2 = parent2
 
     def __str__(self) -> str:
-        p1_str = ""
-        if self.parent1:
-            p1_str = f" p1:{self.parent1.short_string()}"
-        p2_str = ""
-        if self.parent2:
-            p2_str = f" p2:{self.parent2.short_string()}"
+        p1_str = f" p1:{self.parent1.short_string()}" if self.parent1 else ""
+        p2_str = f" p2:{self.parent2.short_string()}" if self.parent2 else ""
         return f"{self.branch} c:{self.commit.short_string()}{p1_str}{p2_str}"
 
 
@@ -36,8 +32,7 @@ class FlatTreeWalker(AbstractWalker):
     def handle_source_node(self, node) -> None:
         if self.rebase_devel and node.parent and node.parent.merged_into:
             self.add("devel", node.revision, node.parent.merged_into.revision)
-            return
-        if node.parent:
+        elif node.parent:
             self.add("devel", node.revision, node.parent.revision)
         elif self.last_merge:
             self.add("devel", node.revision, self.last_merge.parent.revision)
diff --git a/lib/git.py b/lib/git.py
index 53007cb..01d0a15 100644
--- a/lib/git.py
+++ b/lib/git.py
@@ -256,11 +256,11 @@ class Git:
             )
             return any(fnmatch.fnmatch(filename, line) for line in patterns)
 
-    def remove(self, filename):
-        self.repo.index.remove(filename)
-        (self.path / filename).unlink()
+    def remove(self, file: pathlib.Path):
+        self.repo.index.remove(file.name)
+        (self.path / file).unlink()
 
         patterns = self.get_specific_lfs_gitattributes()
-        if filename in patterns:
-            patterns.remove(filename)
+        if file.name in patterns:
+            patterns.remove(file.name)
             self.add_specific_lfs_gitattributes(patterns)
diff --git a/lib/git_exporter.py b/lib/git_exporter.py
index f988205..5f89f94 100644
--- a/lib/git_exporter.py
+++ b/lib/git_exporter.py
@@ -1,5 +1,6 @@
 import logging
 import os
+from pathlib import Path
 
 import yaml
 
@@ -121,10 +122,8 @@ class GitExporter:
             logging.debug(f"Committing {flat}")
             self.commit_flat(db, flat, branch_state)
 
-    def limit_download(self, file):
-        if file.endswith(".spec") or file.endswith(".changes"):
-            return True
-        return False
+    def limit_download(self, file: Path):
+        return file.suffix in (".spec", ".changes")
 
     def commit_flat(self, db, flat, branch_state):
         parents = []
@@ -144,7 +143,7 @@ class GitExporter:
             self.obs.download(
                 flat.commit.project,
                 flat.commit.package,
-                file,
+                file.name,
                 flat.commit.expanded_srcmd5,
                 self.git.path,
                 file_md5=md5,