import packages test does not require setuptools anymore if not avail…

…able

pyproject.toml

@@ -53,10 +53,10 @@ Changelog = "https://github.com/e2nIEE/pandapipes/blob/develop/CHANGELOG.rst"
 [project.optional-dependencies]
 docs = ["numpydoc", "sphinx", "sphinx_rtd_theme", "sphinxcontrib.bibtex", "sphinx-pyproject"]
 plotting = ["plotly", "igraph"]
-test = ["pytest", "pytest-xdist", "nbmake", "setuptools; python_version >= '3.12'"]
+test = ["pytest", "pytest-xdist", "nbmake"]
 all = [
     "numpydoc", "sphinx", "sphinx_rtd_theme", "sphinxcontrib.bibtex",
-    "plotly", "igraph", "pytest", "pytest-xdist", "nbmake", "setuptools; python_version >= '3.12'"
+    "plotly", "igraph", "pytest", "pytest-xdist", "nbmake"
 ]
 
 [tool.setuptools.packages.find]

src/pandapipes/test/test_imports.py

@@ -8,11 +8,28 @@
 
 import pytest
 from pandapipes import pp_dir
-from setuptools import find_packages
+try:
+    from setuptools import find_packages
+    SETUPTOOLS_AVAILABLE = True
+except ImportError:
+    SETUPTOOLS_AVAILABLE = False
 
 
 def test_import_packages():
-    all_packages = find_packages(pp_dir)
+    if SETUPTOOLS_AVAILABLE:
+        all_packages = find_packages(pp_dir)
+    else:
+        all_packages = []
+        for root, dirs, files in os.walk(pp_dir):
+            for file in files:
+                if file != "__init__.py":
+                    continue
+                path = os.path.relpath(root, pp_dir)
+                if path == ".":
+                    continue
+                pck = path.replace(os.sep, ".")
+                all_packages.append(pck)
+
     for pck in all_packages:
         spec = importlib.util.find_spec(os.path.split(pp_dir)[-1] + "." + pck)
         new_module = importlib.util.module_from_spec(spec)