diff --git a/deptry/cli_defaults.py b/deptry/cli_defaults.py
index 31170615..6a789b5e 100644
--- a/deptry/cli_defaults.py
+++ b/deptry/cli_defaults.py
@@ -3,7 +3,7 @@
     "ignore_missing": (),
     "ignore_transitive": (),
     "ignore_misplaced_dev": (),
-    "exclude": ("venv", "\.venv", "tests", "\.git", "setup.py"),
+    "exclude": ("venv", r"\.venv", "tests", r"\.git", "setup.py"),
     "extend_exclude": (),
     "ignore_notebooks": False,
     "skip_obsolete": False,
diff --git a/deptry/dependency_getter/requirements_txt.py b/deptry/dependency_getter/requirements_txt.py
index 069f418c..662268f8 100644
--- a/deptry/dependency_getter/requirements_txt.py
+++ b/deptry/dependency_getter/requirements_txt.py
@@ -104,7 +104,7 @@ def _check_if_dependency_is_conditional(line: str) -> bool:
 
     @staticmethod
     def _line_is_url(line: str) -> Optional[Match[str]]:
-        return re.search("^(http|https|git\+https)", line)
+        return re.search(r"^(http|https|git\+https)", line)
 
     @staticmethod
     def _extract_name_from_url(line: str) -> Optional[str]:
@@ -114,12 +114,12 @@ def _extract_name_from_url(line: str) -> Optional[str]:
             return match.group(1)
 
         # for url like git+https://github.com/name/python-module.git@0d6dc38d58
-        match = re.search("\/((?:(?!\/).)*?)\.git", line)
+        match = re.search(r"\/((?:(?!\/).)*?)\.git", line)
         if match:
             return match.group(1)
 
         # for url like https://github.com/urllib3/urllib3/archive/refs/tags/1.26.8.zip
-        match = re.search("\/((?:(?!\/).)*?)\/archive\/", line)
+        match = re.search(r"\/((?:(?!\/).)*?)\/archive\/", line)
         if match:
             return match.group(1)
 
diff --git a/deptry/notebook_import_extractor.py b/deptry/notebook_import_extractor.py
index de605e3f..904b89ae 100644
--- a/deptry/notebook_import_extractor.py
+++ b/deptry/notebook_import_extractor.py
@@ -27,7 +27,7 @@ def extract(self, path_to_ipynb: Path) -> List[str]:
 
     @staticmethod
     def _read_ipynb_file(path_to_ipynb: Path) -> Dict[str, Any]:
-        with open(path_to_ipynb, "r") as f:
+        with open(path_to_ipynb) as f:
             notebook: Dict[str, Any] = json.load(f)
         return notebook
 
diff --git a/deptry/python_file_finder.py b/deptry/python_file_finder.py
index ea227a25..981320eb 100644
--- a/deptry/python_file_finder.py
+++ b/deptry/python_file_finder.py
@@ -27,7 +27,7 @@ def get_all_python_files_in(self, directory: Path) -> List[Path]:
         py_regex = re.compile(r".*\.py$") if self.ignore_notebooks else re.compile(r".*\.py$|.*\.ipynb$")
 
         for root, dirs, files in os.walk(directory, topdown=True):
-            root_without_trailing_dotslash = re.sub("^\./", "", root)
+            root_without_trailing_dotslash = re.sub(r"^\./", "", root)
             if self.exclude and ignore_regex.match(root_without_trailing_dotslash):
                 dirs[:] = []
                 continue
diff --git a/tests/cli/test_cli.py b/tests/cli/test_cli.py
index 39c9c639..1a9094e5 100644
--- a/tests/cli/test_cli.py
+++ b/tests/cli/test_cli.py
@@ -93,7 +93,7 @@ def test_cli_with_json_output(dir_with_venv_installed):
 
         # assert that there is json output
         subprocess.run(shlex.split("poetry run deptry . -o deptry.json"), capture_output=True, text=True)
-        with open("deptry.json", "r") as f:
+        with open("deptry.json") as f:
             data = json.load(f)
         assert set(data["obsolete"]) == {"isort", "requests"}
         assert set(data["missing"]) == {"white"}
diff --git a/tests/test_json_writer.py b/tests/test_json_writer.py
index 704d9055..5e0e567c 100644
--- a/tests/test_json_writer.py
+++ b/tests/test_json_writer.py
@@ -8,7 +8,7 @@ def test_simple(tmp_path):
     with run_within_dir(tmp_path):
         JsonWriter(json_output="output.json").write(issues={"one": "two", "three": "four"})
 
-        with open("output.json", "r") as f:
+        with open("output.json") as f:
             data = json.load(f)
 
         assert data["one"] == "two"