diff --git a/tests/test_examples.py b/tests/test_examples.py
index 994eb8c0..9e2b7cc0 100644
--- a/tests/test_examples.py
+++ b/tests/test_examples.py
@@ -12,10 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
 import random
 from glob import glob
-from os import listdir, walk
-from os.path import basename, dirname, getsize, isdir, isfile, join, normpath
 
 import pytest
 
@@ -32,24 +31,26 @@ def pytest_generate_tests(metafunc):
     examples_dirs = []
 
     # repo examples
-    examples_dirs.append(normpath(join(dirname(__file__), "..", "examples")))
+    examples_dirs.append(
+        os.path.normpath(os.path.join(os.path.dirname(__file__), "..", "examples"))
+    )
 
     # dev/platforms
     for pkg in PlatformPackageManager().get_installed():
         p = PlatformFactory.new(pkg)
-        examples_dir = join(p.get_dir(), "examples")
-        assert isdir(examples_dir)
-        examples_dirs.append(examples_dir)
+        examples_dir = os.path.join(p.get_dir(), "examples")
+        if os.path.isdir(examples_dir):
+            examples_dirs.append(examples_dir)
 
     project_dirs = []
     for examples_dir in examples_dirs:
         candidates = {}
-        for root, _, files in walk(examples_dir):
+        for root, _, files in os.walk(examples_dir):
             if "platformio.ini" not in files or ".skiptest" in files:
                 continue
             if "zephyr-" in root and PY2:
                 continue
-            group = basename(root)
+            group = os.path.basename(root)
             if "-" in group:
                 group = group.split("-", 1)[0]
             if group not in candidates:
@@ -67,7 +68,7 @@ def test_run(pioproject_dir):
     with fs.cd(pioproject_dir):
         config = ProjectConfig()
         build_dir = config.get_optional_dir("build")
-        if isdir(build_dir):
+        if os.path.isdir(build_dir):
             fs.rmtree(build_dir)
 
         env_names = config.envs()
@@ -77,18 +78,18 @@ def test_run(pioproject_dir):
         if result["returncode"] != 0:
             pytest.fail(str(result))
 
-        assert isdir(build_dir)
+        assert os.path.isdir(build_dir)
 
         # check .elf file
-        for item in listdir(build_dir):
-            if not isdir(item):
+        for item in os.listdir(build_dir):
+            if not os.path.isdir(item):
                 continue
-            assert isfile(join(build_dir, item, "firmware.elf"))
+            assert os.path.isfile(os.path.join(build_dir, item, "firmware.elf"))
             # check .hex or .bin files
             firmwares = []
             for ext in ("bin", "hex"):
-                firmwares += glob(join(build_dir, item, "firmware*.%s" % ext))
+                firmwares += glob(os.path.join(build_dir, item, "firmware*.%s" % ext))
             if not firmwares:
                 pytest.fail("Missed firmware file")
             for firmware in firmwares:
-                assert getsize(firmware) > 0
+                assert os.path.getsize(firmware) > 0