diff --git a/app/libros/apps.py b/app/libros/apps.py
index 085be30..bccaec3 100644
--- a/app/libros/apps.py
+++ b/app/libros/apps.py
@@ -2,5 +2,5 @@ from django.apps import AppConfig
 
 
 class LibrosConfig(AppConfig):
-    default_auto_field = 'django.db.models.BigAutoField'
-    name = 'app.libros'
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "app.libros"
diff --git a/app/libros/models.py b/app/libros/models.py
index 7136479..9b1f313 100644
--- a/app/libros/models.py
+++ b/app/libros/models.py
@@ -22,4 +22,4 @@ class Libros(models.Model):
         verbose_name_plural = "Libros"
 
     def __str__(self):
-        return self.title
\ No newline at end of file
+        return self.title
diff --git a/app/libros/views.py b/app/libros/views.py
index ad927c9..b1771b7 100644
--- a/app/libros/views.py
+++ b/app/libros/views.py
@@ -14,9 +14,8 @@ def ping(request):
 
 
 class LibrosList(APIView):
-
     def get(self, request):
-        libros = Libros.objects.all().order_by('created_at')
+        libros = Libros.objects.all().order_by("created_at")
         serializer = LibroSerializer(libros, many=True)
         return Response(serializer.data, status=status.HTTP_200_OK)
 
@@ -29,7 +28,6 @@ class LibrosList(APIView):
 
 
 class LibrosDetails(APIView):
-
     def get(self, request, pk):
         libro = Libros.objects.filter(pk=pk).first()
         if libro:
@@ -37,7 +35,6 @@ class LibrosDetails(APIView):
             return Response(serializer.data, status=status.HTTP_200_OK)
         return Response(status=status.HTTP_404_NOT_FOUND)
 
-
     def put(self, request, pk):
         libro = Libros.objects.filter(pk=pk).first()
         serializer = LibroSerializer(libro, data=request.data)
@@ -46,7 +43,6 @@ class LibrosDetails(APIView):
             return Response(serializer.data, status=status.HTTP_200_OK)
         return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
 
-
     def delete(self, request, pk):
         libro = Libros.objects.filter(pk=pk).first()
         if libro:
diff --git a/manage.py b/manage.py
index 5cd4202..88c5155 100755
--- a/manage.py
+++ b/manage.py
@@ -6,7 +6,7 @@ import sys
 
 def main():
     """Run administrative tasks."""
-    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'proyecto.settings')
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "proyecto.settings")
     try:
         from django.core.management import execute_from_command_line
     except ImportError as exc:
@@ -18,5 +18,5 @@ def main():
     execute_from_command_line(sys.argv)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()
diff --git a/proyecto/asgi.py b/proyecto/asgi.py
index a3b9f57..ba5272b 100644
--- a/proyecto/asgi.py
+++ b/proyecto/asgi.py
@@ -11,6 +11,6 @@ import os
 
 from django.core.asgi import get_asgi_application
 
-os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'proyecto.settings')
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "proyecto.settings")
 
 application = get_asgi_application()
diff --git a/proyecto/settings.py b/proyecto/settings.py
index dcfdbf6..d7d113d 100644
--- a/proyecto/settings.py
+++ b/proyecto/settings.py
@@ -20,7 +20,7 @@ BASE_DIR = Path(__file__).resolve().parent.parent
 # See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/
 
 # SECURITY WARNING: keep the secret key used in production secret!
-SECRET_KEY = 'django-insecure-+j!b+4cv@q0$^$2%5o+&c&@!hf1bfgpl#f^71dfgzijt2fek9#'
+SECRET_KEY = "django-insecure-+j!b+4cv@q0$^$2%5o+&c&@!hf1bfgpl#f^71dfgzijt2fek9#"
 
 # SECURITY WARNING: don't run with debug turned on in production!
 DEBUG = True
@@ -31,54 +31,54 @@ ALLOWED_HOSTS = []
 # Application definition
 
 INSTALLED_APPS = [
-    'django.contrib.admin',
-    'django.contrib.auth',
-    'django.contrib.contenttypes',
-    'django.contrib.sessions',
-    'django.contrib.messages',
-    'django.contrib.staticfiles',
-    'rest_framework', # nuevo
-    'app.libros', # nuevo
+    "django.contrib.admin",
+    "django.contrib.auth",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+    "rest_framework",  # nuevo
+    "app.libros",  # nuevo
 ]
 
 MIDDLEWARE = [
-    'django.middleware.security.SecurityMiddleware',
-    'django.contrib.sessions.middleware.SessionMiddleware',
-    'django.middleware.common.CommonMiddleware',
-    'django.middleware.csrf.CsrfViewMiddleware',
-    'django.contrib.auth.middleware.AuthenticationMiddleware',
-    'django.contrib.messages.middleware.MessageMiddleware',
-    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+    "django.middleware.security.SecurityMiddleware",
+    "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.middleware.common.CommonMiddleware",
+    "django.middleware.csrf.CsrfViewMiddleware",
+    "django.contrib.auth.middleware.AuthenticationMiddleware",
+    "django.contrib.messages.middleware.MessageMiddleware",
+    "django.middleware.clickjacking.XFrameOptionsMiddleware",
 ]
 
-ROOT_URLCONF = 'proyecto.urls'
+ROOT_URLCONF = "proyecto.urls"
 
 TEMPLATES = [
     {
-        'BACKEND': 'django.template.backends.django.DjangoTemplates',
-        'DIRS': [],
-        'APP_DIRS': True,
-        'OPTIONS': {
-            'context_processors': [
-                'django.template.context_processors.debug',
-                'django.template.context_processors.request',
-                'django.contrib.auth.context_processors.auth',
-                'django.contrib.messages.context_processors.messages',
+        "BACKEND": "django.template.backends.django.DjangoTemplates",
+        "DIRS": [],
+        "APP_DIRS": True,
+        "OPTIONS": {
+            "context_processors": [
+                "django.template.context_processors.debug",
+                "django.template.context_processors.request",
+                "django.contrib.auth.context_processors.auth",
+                "django.contrib.messages.context_processors.messages",
             ],
         },
     },
 ]
 
-WSGI_APPLICATION = 'proyecto.wsgi.application'
+WSGI_APPLICATION = "proyecto.wsgi.application"
 
 
 # Database
 # https://docs.djangoproject.com/en/3.2/ref/settings/#databases
 
 DATABASES = {
-    'default': {
-        'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': BASE_DIR / 'db.sqlite3',
+    "default": {
+        "ENGINE": "django.db.backends.sqlite3",
+        "NAME": BASE_DIR / "db.sqlite3",
     }
 }
 
@@ -88,16 +88,16 @@ DATABASES = {
 
 AUTH_PASSWORD_VALIDATORS = [
     {
-        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
+        "NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator",
     },
     {
-        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
+        "NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",
     },
     {
-        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
+        "NAME": "django.contrib.auth.password_validation.CommonPasswordValidator",
     },
     {
-        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
+        "NAME": "django.contrib.auth.password_validation.NumericPasswordValidator",
     },
 ]
 
@@ -105,9 +105,9 @@ AUTH_PASSWORD_VALIDATORS = [
 # Internationalization
 # https://docs.djangoproject.com/en/3.2/topics/i18n/
 
-LANGUAGE_CODE = 'en-us'
+LANGUAGE_CODE = "en-us"
 
-TIME_ZONE = 'UTC'
+TIME_ZONE = "UTC"
 
 USE_I18N = True
 
@@ -119,11 +119,11 @@ USE_TZ = True
 # Static files (CSS, JavaScript, Images)
 # https://docs.djangoproject.com/en/3.2/howto/static-files/
 
-STATIC_URL = '/static/'
+STATIC_URL = "/static/"
 
 # Default primary key field type
 # https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field
 
-DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
+DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
 
-AUTH_USER_MODEL = 'libros.CustomUser'
\ No newline at end of file
+AUTH_USER_MODEL = "libros.CustomUser"
diff --git a/proyecto/urls.py b/proyecto/urls.py
index e880062..19c11e9 100644
--- a/proyecto/urls.py
+++ b/proyecto/urls.py
@@ -6,4 +6,4 @@ from django.urls import path, include
 urlpatterns = [
     path("admin/", admin.site.urls),
     path("", include("app.libros.urls")),
-]
\ No newline at end of file
+]
diff --git a/proyecto/wsgi.py b/proyecto/wsgi.py
index 022bae0..4893b71 100644
--- a/proyecto/wsgi.py
+++ b/proyecto/wsgi.py
@@ -11,6 +11,6 @@ import os
 
 from django.core.wsgi import get_wsgi_application
 
-os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'proyecto.settings')
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "proyecto.settings")
 
 application = get_wsgi_application()
diff --git a/tests/libros/test_create_model.py b/tests/libros/test_create_model.py
index bfa7e2b..9f9afe9 100644
--- a/tests/libros/test_create_model.py
+++ b/tests/libros/test_create_model.py
@@ -4,6 +4,7 @@ import pytest
 
 from app.libros.models import Libros
 
+
 @pytest.mark.django_db
 def test_libros_model():
 
@@ -26,4 +27,4 @@ def test_libros_model():
     assert libro.author == "Isaac Asimov"
     assert libro.created_at
     assert libro.updated_at
-    assert str(libro) == libro.title
\ No newline at end of file
+    assert str(libro) == libro.title
diff --git a/tests/libros/test_serializers.py b/tests/libros/test_serializers.py
index ac12841..78c29cd 100644
--- a/tests/libros/test_serializers.py
+++ b/tests/libros/test_serializers.py
@@ -2,6 +2,7 @@
 
 from app.libros.serializers import LibroSerializer
 
+
 def test_valid_libro_serializer():
     valid_serializer_data = {
         "title": "Raising Arizona",
diff --git a/tests/libros/test_views.py b/tests/libros/test_views.py
index f26a529..fd79d20 100644
--- a/tests/libros/test_views.py
+++ b/tests/libros/test_views.py
@@ -20,7 +20,7 @@ def test_add_book(client):
             "author": "Isaac Asimov",
             "year": "1955",
         },
-        content_type="application/json"
+        content_type="application/json",
     )
 
     # Then
@@ -40,7 +40,7 @@ def test_get_single_book(client):
         genre="Ciencia Ficción",
         author="Isaac Asimov",
         year="1955",
-        )
+    )
 
     # When
     resp = client.get(f"/api/libros/{libro.id}/")
@@ -154,7 +154,7 @@ def test_update_book(client):
             "author": "Frank Herbert",
             "year": "1965",
         },
-        content_type="application/json"
+        content_type="application/json",
     )
 
     # Then
@@ -195,8 +195,8 @@ def test_update_book_invalid_json(client):
             "foo": "Dune",
             "boo": "Ciencia Ficción",
         },
-        content_type="application/json"
+        content_type="application/json",
     )
 
     # Then
-    assert resp.status_code == 400
\ No newline at end of file
+    assert resp.status_code == 400
diff --git a/tests/test_ejemplo.py b/tests/test_ejemplo.py
index db7f75f..e351af8 100644
--- a/tests/test_ejemplo.py
+++ b/tests/test_ejemplo.py
@@ -1,3 +1,3 @@
 # Las funciones deben empezar por "test_"
 def test_titulo():
-    assert "canción de hielo y fuego" != "juego de tronos"
\ No newline at end of file
+    assert "canción de hielo y fuego" != "juego de tronos"
diff --git a/tests/test_ping.py b/tests/test_ping.py
index 91fb861..2e48a15 100644
--- a/tests/test_ping.py
+++ b/tests/test_ping.py
@@ -1,9 +1,10 @@
 import json
 from django.urls import reverse
 
+
 def test_ping(client):
     url = reverse("ping")
     response = client.get(url)
     content = json.loads(response.content)
     assert response.status_code == 200
-    assert content["ping"] == "pong!"
\ No newline at end of file
+    assert content["ping"] == "pong!"