diff --git a/src/otc/__init__.py b/src/otc/__init__.py
index dedab9af..bae05242 100644
--- a/src/otc/__init__.py
+++ b/src/otc/__init__.py
@@ -1,4 +1,3 @@
 """Support for custom code."""
 
-
 __version__ = "0.0.1"
diff --git a/src/otc/data/dataloader.py b/src/otc/data/dataloader.py
index bb5d5c3f..4290d5f7 100644
--- a/src/otc/data/dataloader.py
+++ b/src/otc/data/dataloader.py
@@ -3,6 +3,7 @@
 Adapted from here:
 https://discuss.pytorch.org/t/dataloader-much-slower-than-manual-batching/27014/6
 """
+
 from __future__ import annotations
 
 from typing import Any
diff --git a/src/otc/data/make_dataset.py b/src/otc/data/make_dataset.py
index 28444173..acb29916 100644
--- a/src/otc/data/make_dataset.py
+++ b/src/otc/data/make_dataset.py
@@ -2,6 +2,7 @@
 
 See `notebooks/` for further details.
 """
+
 import logging
 import logging.config
 from pathlib import Path
diff --git a/src/otc/metrics/metrics.py b/src/otc/metrics/metrics.py
index ce0bad72..3d3e826c 100644
--- a/src/otc/metrics/metrics.py
+++ b/src/otc/metrics/metrics.py
@@ -2,6 +2,7 @@
 
 See: https://hagstromer.org/2020/11/23/overestimated-effective-spreads/ for explanation.
 """
+
 from __future__ import annotations
 
 from typing import Literal
diff --git a/src/otc/models/activation.py b/src/otc/models/activation.py
index 3b4167fc..962f1ef1 100644
--- a/src/otc/models/activation.py
+++ b/src/otc/models/activation.py
@@ -3,6 +3,7 @@
 Adapted from:
 https://github.com/Yura52/rtdl/blob/main/rtdl/functional.py
 """
+
 import torch
 import torch.nn.functional as F  # noqa: N812
 from torch import nn
diff --git a/src/otc/models/fttransformer.py b/src/otc/models/fttransformer.py
index 73bc6208..627e5cca 100644
--- a/src/otc/models/fttransformer.py
+++ b/src/otc/models/fttransformer.py
@@ -3,6 +3,7 @@
 Adapted from:
 https://github.com/Yura52/rtdl/
 """
+
 from __future__ import annotations
 
 import enum
diff --git a/src/otc/models/selftraining.py b/src/otc/models/selftraining.py
index d50e5fd5..fc78a396 100644
--- a/src/otc/models/selftraining.py
+++ b/src/otc/models/selftraining.py
@@ -2,6 +2,7 @@
 
 Based on sklearn implementation.
 """
+
 from __future__ import annotations
 
 import warnings
diff --git a/src/otc/models/train_model.py b/src/otc/models/train_model.py
index 4ac8d6c2..ee9fba3f 100644
--- a/src/otc/models/train_model.py
+++ b/src/otc/models/train_model.py
@@ -3,6 +3,7 @@
 Currently classical rules and gradient boosted trees are supported.
 
 """
+
 import logging
 import logging.config
 import pickle
diff --git a/src/otc/models/transformer_classifier.py b/src/otc/models/transformer_classifier.py
index 3aea6ea8..8fbbbc39 100644
--- a/src/otc/models/transformer_classifier.py
+++ b/src/otc/models/transformer_classifier.py
@@ -2,6 +2,7 @@
 
 Can be used as a consistent interface for evaluation and tuning.
 """
+
 from __future__ import annotations
 
 import gc
diff --git a/src/otc/optim/early_stopping.py b/src/otc/optim/early_stopping.py
index 3aab4ddf..5fac2418 100644
--- a/src/otc/optim/early_stopping.py
+++ b/src/otc/optim/early_stopping.py
@@ -3,7 +3,6 @@
 Adapted from here: https://bit.ly/3tTnyLU.
 """
 
-
 import logging
 import logging.config
 import math
diff --git a/src/otc/optim/scheduler.py b/src/otc/optim/scheduler.py
index 436d5005..bff8f7cb 100644
--- a/src/otc/optim/scheduler.py
+++ b/src/otc/optim/scheduler.py
@@ -1,4 +1,5 @@
 """Learnin rate scheduler with linear warmup phase and cosine decay."""
+
 from typing import List
 
 import numpy as np
diff --git a/src/otc/utils/check_formalia.py b/src/otc/utils/check_formalia.py
index 82e79573..6bf92aef 100644
--- a/src/otc/utils/check_formalia.py
+++ b/src/otc/utils/check_formalia.py
@@ -2,6 +2,7 @@
 
 TODO: add more tests.
 """
+
 import os
 import re
 from pathlib import Path
diff --git a/src/otc/utils/check_url.py b/src/otc/utils/check_url.py
index 24cf485e..1dc3706e 100644
--- a/src/otc/utils/check_url.py
+++ b/src/otc/utils/check_url.py
@@ -2,6 +2,7 @@
 
 Looks into .bib and .tex files.
 """
+
 import os
 import re
 from pathlib import Path
diff --git a/tests/test_dataset.py b/tests/test_dataset.py
index 7c135702..4207d225 100644
--- a/tests/test_dataset.py
+++ b/tests/test_dataset.py
@@ -4,7 +4,6 @@
 categorical data.
 """
 
-
 import numpy as np
 import pandas as pd
 import pytest
diff --git a/tests/test_objective.py b/tests/test_objective.py
index 1eb32137..19b74c1b 100644
--- a/tests/test_objective.py
+++ b/tests/test_objective.py
@@ -1,4 +1,5 @@
 """Tests for Objectives."""
+
 import datetime as dt
 from pathlib import Path
 from unittest.mock import patch