Revert "Use pytest_notebook to test whether notebooks run without errors"

This reverts commit 07649a9.

Author: birgits

example/test_examples.py

@@ -4,10 +4,14 @@
 """
 
 import os
+import subprocess
+import tempfile
+import nbformat
+import sys
 from example import modelchain_example as mc_e
 from example import turbine_cluster_modelchain_example as tc_mc_e
 from numpy.testing import assert_allclose
-import pytest_notebook
+import pytest
 
 
 class TestExamples:
@@ -53,29 +57,50 @@ def test_turbine_cluster_modelchain_example_flh(self):
 
     def _notebook_run(self, path):
         """
-        Execute a notebook and collect output.
+        Execute a notebook via nbconvert and collect output.
         Returns (parsed nb object, execution errors)
         """
-        dirname, nb_name = os.path.split(path)
+        dirname, __ = os.path.split(path)
         os.chdir(dirname)
-        notebook = pytest_notebook.notebook.load_notebook(path=nb_name)
-        result = pytest_notebook.execution.execute_notebook(
-            notebook,
-            with_coverage=False,
-            timeout=600,
-        )
-        return result.exec_error
+        with tempfile.NamedTemporaryFile(suffix=".ipynb") as fout:
+            args = [
+                "jupyter",
+                "nbconvert",
+                "--to",
+                "notebook",
+                "--execute",
+                "--ExecutePreprocessor.timeout=60",
+                "--output",
+                fout.name,
+                path,
+            ]
+            subprocess.check_call(args)
+
+            fout.seek(0)
+            nb = nbformat.read(fout, nbformat.current_nbformat)
+
+        errors = [
+            output
+            for cell in nb.cells
+            if "outputs" in cell
+            for output in cell["outputs"]
+            if output.output_type == "error"
+        ]
+
+        return nb, errors
 
+    @pytest.mark.skipif(sys.version_info < (3, 6), reason="requires python3.6")
     def test_modelchain_example_ipynb(self):
         dir_path = os.path.dirname(os.path.realpath(__file__))
-        errors = self._notebook_run(
+        nb, errors = self._notebook_run(
             os.path.join(dir_path, "modelchain_example.ipynb")
         )
-        assert errors is None
+        assert errors == []
 
+    @pytest.mark.skipif(sys.version_info < (3, 6), reason="requires python3.6")
     def test_turbine_cluster_modelchain_example_ipynb(self):
         dir_path = os.path.dirname(os.path.realpath(__file__))
-        errors = self._notebook_run(
+        nb, errors = self._notebook_run(
             os.path.join(dir_path, "turbine_cluster_modelchain_example.ipynb")
         )
-        assert errors is None
+        assert errors == []

setup.py

@@ -30,9 +30,9 @@ def read(fname):
             "pytest",
             "jupyter",
             "sphinx_rtd_theme",
+            "nbformat",
             "numpy",
             "matplotlib",
-            "pytest-notebook",
         ]
     },
 )