diff --git a/src/pygenstability/__init__.py b/src/pygenstability/__init__.py
index 36f62b5..2e6ee8c 100644
--- a/src/pygenstability/__init__.py
+++ b/src/pygenstability/__init__.py
@@ -1,4 +1,5 @@
 """Import main functions."""
+
 from pygenstability.constructors import *
 from pygenstability.io import load_results
 from pygenstability.io import save_results
diff --git a/src/pygenstability/app.py b/src/pygenstability/app.py
index 6fd1d17..ed941e7 100644
--- a/src/pygenstability/app.py
+++ b/src/pygenstability/app.py
@@ -1,4 +1,5 @@
 """Command line interface."""
+
 import pickle
 from pathlib import Path
 
diff --git a/src/pygenstability/constructors.py b/src/pygenstability/constructors.py
index ee6aba5..743d2ca 100644
--- a/src/pygenstability/constructors.py
+++ b/src/pygenstability/constructors.py
@@ -13,6 +13,7 @@
 :math:`\boldsymbol{1}` is the vector of ones, and we denote the diagonal degree matrix by
 :math:`D=\mathrm{diag}(d)`.
 """
+
 import logging
 import sys
 
diff --git a/src/pygenstability/contrib/sankey.py b/src/pygenstability/contrib/sankey.py
index 45f9407..6e83ef9 100644
--- a/src/pygenstability/contrib/sankey.py
+++ b/src/pygenstability/contrib/sankey.py
@@ -1,4 +1,5 @@
 """Sankey diagram plots."""
+
 import numpy as np  # pragma: no cover
 import plotly.graph_objects as go  # pragma: no cover
 from plotly.offline import plot  # pragma: no cover
diff --git a/src/pygenstability/io.py b/src/pygenstability/io.py
index 34af04e..5250aae 100644
--- a/src/pygenstability/io.py
+++ b/src/pygenstability/io.py
@@ -1,4 +1,5 @@
 """I/O functions."""
+
 import pickle
 
 
diff --git a/src/pygenstability/optimal_scales.py b/src/pygenstability/optimal_scales.py
index efa3a79..be1a267 100644
--- a/src/pygenstability/optimal_scales.py
+++ b/src/pygenstability/optimal_scales.py
@@ -1,4 +1,5 @@
 """Detect optimal scales from a scale scan."""
+
 import numpy as np
 import pandas as pd
 from numpy.lib.stride_tricks import as_strided
diff --git a/src/pygenstability/plotting.py b/src/pygenstability/plotting.py
index ee4f19f..74a0451 100644
--- a/src/pygenstability/plotting.py
+++ b/src/pygenstability/plotting.py
@@ -1,4 +1,5 @@
 """Plotting functions."""
+
 import logging
 import os
 
diff --git a/src/pygenstability/pygenstability.py b/src/pygenstability/pygenstability.py
index 0eda967..d526655 100644
--- a/src/pygenstability/pygenstability.py
+++ b/src/pygenstability/pygenstability.py
@@ -11,6 +11,7 @@
 Markov Stability setting, and can be parametrised via built-in constructors, or specified by
 the user via the constructor module.
 """
+
 import itertools
 import logging
 import multiprocessing