diff --git a/dc-ops b/dc-ops
index 2651f96..311fe48 100755
--- a/dc-ops
+++ b/dc-ops
@@ -5,6 +5,8 @@
 # CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)
 # for civil use only
 
+# pylint: disable=missing-module-docstring,invalid-name
+
 import argparse
 import logging as log
 from pathlib import Path
@@ -15,12 +17,12 @@ from lib.helper import run_subprocess, update_git_repo, do_selfupdate
 
 # read config file
 configfile = Path(__file__).with_name("config.yml")
-with configfile.open("r") as f:
+with configfile.open("r", encoding="utf-8") as f:
     cfg = yaml.safe_load(f.read())
 
 # fmt: off
 parser = argparse.ArgumentParser()
-parser.add_argument("--ignore-git-status", action="store_true", help="continue even if there are no new commits")  # noqa
+parser.add_argument("--ignore-git-status", action="store_true", help="continue even if there are no new commits")
 parser.add_argument("--loglevel", help="set loglevel (overrides config file)")
 args = parser.parse_args()
 # fmt: on
@@ -47,7 +49,7 @@ for stack in cfg["stacks"]:
 
     # header
     stackdir = stack["dir"]
-    log.info(f"processing: {stackdir}")
+    log.info("processing: %s", stackdir)
 
     # update repo and check for new commits
     if not update_git_repo(stackdir, args.ignore_git_status):
@@ -63,7 +65,7 @@ for stack in cfg["stacks"]:
     # (or just for the directory if no compose-file defined)
     composefiles = stack.get("compose-files", ["docker-compose.yml"])
     for composefile in composefiles:
-        log.info(f"-> bringing up {composefile}")
+        log.info("-> bringing up %s", composefile)
         if not run_subprocess(
             f"docker compose --file {composefile} up --detach {composeopts}",
             stackdir,
diff --git a/lib/helper.py b/lib/helper.py
index 2bb56d5..1fbe286 100644
--- a/lib/helper.py
+++ b/lib/helper.py
@@ -1,3 +1,5 @@
+# pylint: disable=missing-module-docstring
+
 import logging as log
 import subprocess
 import sys
@@ -32,7 +34,9 @@ def run_subprocess(command: str, workdir: str) -> bool:
         bool: False if subprocess fails
     """
     try:
-        log.debug(subprocess.run(command.split(" "), cwd=workdir, text=True))
+        log.debug(
+            subprocess.run(command.split(" "), cwd=workdir, text=True, check=False)
+        )
     except subprocess.CalledProcessError:
         return False
 
@@ -62,7 +66,7 @@ def update_git_repo(repo_path: str, ignore_git_status: bool) -> bool:
         try:
             fetch_res = repo.remotes.origin.fetch()[0]
         except git.exc.GitCommandError as e:
-            log.error("-> " + str(e))
+            log.error("-> %s ", str(e))
             return False
 
         # check for new commits
@@ -72,9 +76,9 @@ def update_git_repo(repo_path: str, ignore_git_status: bool) -> bool:
 
     # pull remote changes to local branch
     try:
-        log.info("-> " + repo.git.pull())
+        log.info("-> %s", repo.git.pull())
     except git.exc.GitCommandError as e:
-        log.error("-> " + str(e))
+        log.error("-> %s", str(e))
         return False
 
     return True