diff --git a/_doc/conf.py b/_doc/conf.py
index 61c0ab4..3020520 100644
--- a/_doc/conf.py
+++ b/_doc/conf.py
@@ -4,7 +4,6 @@
 from sphinx_runpython.conf_helper import has_dvipng, has_dvisvgm
 from mlstatpy import __version__
 
-
 extensions = [
     "nbsphinx",
     "sphinx.ext.autodoc",
diff --git a/_doc/notebooks/dsgarden/correlation_non_lineaire.ipynb b/_doc/notebooks/dsgarden/correlation_non_lineaire.ipynb
index 009ddf4..f2c0980 100644
--- a/_doc/notebooks/dsgarden/correlation_non_lineaire.ipynb
+++ b/_doc/notebooks/dsgarden/correlation_non_lineaire.ipynb
@@ -2918,7 +2918,6 @@
    "source": [
     "import numpy as np\n",
     "\n",
-    "\n",
     "rs = np.random.RandomState(seed=0)\n",
     "\n",
     "\n",
diff --git a/_doc/notebooks/image/segment_detection.ipynb b/_doc/notebooks/image/segment_detection.ipynb
index 18c26dd..87d3ebd 100644
--- a/_doc/notebooks/image/segment_detection.ipynb
+++ b/_doc/notebooks/image/segment_detection.ipynb
@@ -161,7 +161,6 @@
    "source": [
     "from PIL import ImageFilter\n",
     "\n",
-    "\n",
     "pilimg = (\n",
     "    pilimg.filter(ImageFilter.BLUR)\n",
     "    .filter(ImageFilter.BLUR)\n",
diff --git a/_doc/notebooks/ml/neural_tree.ipynb b/_doc/notebooks/ml/neural_tree.ipynb
index 9457d7e..97ab6ec 100644
--- a/_doc/notebooks/ml/neural_tree.ipynb
+++ b/_doc/notebooks/ml/neural_tree.ipynb
@@ -728,7 +728,6 @@
    "source": [
     "from sklearn.linear_model import LogisticRegression\n",
     "\n",
-    "\n",
     "clsX = numpy.empty((100, 2), dtype=numpy.float64)\n",
     "clsX[:50] = numpy.random.randn(50, 2)\n",
     "clsX[50:] = numpy.random.randn(50, 2) + 2\n",