diff --git a/pyproject.toml b/pyproject.toml
index 65ad501..9c9fbbb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -43,5 +43,5 @@ line-length = 100
 
 [tool.ruff.lint]
 select = [ "A", "B", "C90", "D", "E", "EM", "F", "I", "N", "PTH", "RUF", "W",]
-ignore = ["D103", "D102", "D101", "D100", "D107", "D104", "D105", "EM101"]
+ignore = ["D103", "D102", "D101", "D100", "D107", "D104", "D105", "EM101", "N802", "N815", "EM102"]
 exclude = ["windows/*", "tests/*"]
diff --git a/src/pireal/core/relation.py b/src/pireal/core/relation.py
index 2e7c4a9..0160bc0 100644
--- a/src/pireal/core/relation.py
+++ b/src/pireal/core/relation.py
@@ -20,18 +20,18 @@
 
 # This module is based on Relational: <https://github.com/ltworf/relational>
 
-import re
 import itertools
+import re
 
-from pireal.utils import eval_expr
-from pireal.core.rtypes import RType
 from pireal.core.ordered_set import OrderedSet
+from pireal.core.rtypes import RType
+from pireal.utils import eval_expr
 
 IS_VALID_FIELD_NAME = re.compile("^[_á-úa-zA-Z][_á-úa-zA-Z0-9]*$")
 
 
 class Error(Exception):
-    """Base exception"""
+    """Base exception."""
 
 
 class FieldError(Error):
@@ -43,7 +43,7 @@ def __init__(self, campo, msg=None):
 
 
 class InvalidFieldNameError(FieldError):
-    """Excepción lanzada cuando un nombre de campo no es válido"""
+    """Excepción lanzada cuando un nombre de campo no es válido."""
 
     def __init__(self, campo, msg=None):
         super().__init__(
@@ -59,7 +59,7 @@ def __init__(self, campo, msg=None):
 
 
 class FieldNotInHeaderError(FieldError):
-    """Excepción lanzada cuando un campo no existe en la relación"""
+    """Excepción lanzada cuando un campo no existe en la relación."""
 
     def __init__(self, campo, relacion, msg=None):
         super().__init__(
@@ -69,8 +69,11 @@ def __init__(self, campo, relacion, msg=None):
 
 
 class WrongSizeError(Error):
-    """Excepción lanzada cuando se trata de insertar un tamaño de
-    tuplas diferente a los que acepta la relación"""
+    """Wrong Size.
+
+    Excepción lanzada cuando se trata de insertar un tamaño de
+    tuplas diferente a los que acepta la relación
+    """
 
     def __init__(self, expected, got, msg=None):
         if msg is None:
@@ -89,13 +92,13 @@ class UnionCompatibleError(Error):
 
 
 def union_compatible(operation):
-    """Decorador que comprueba que dos relaciones sean compatibles"""
+    """Decorador que comprueba que dos relaciones sean compatibles."""
 
     def inner(self, *args, **kwargs):
         header_other = args[0].header
         if len(self._header) != len(header_other):
             raise UnionCompatibleError(
-                "Union not compatible for '{}'".format(operation.__name__)
+                f"Union not compatible for '{operation.__name__}'"
             )
         return operation(self, *args, **kwargs)
 
@@ -134,8 +137,7 @@ def update(self, row, column, new_value):
         self.content[row] = tuple(old)
 
     def append_row(self):
-        """Agrega una fila/tupla al final"""
-
+        """Agrega una fila/tupla al final."""
         nulls = []
         for _ in range(self.degree()):
             nulls.append("null ({})".format(self._null_count))
@@ -143,28 +145,25 @@ def append_row(self):
         self.insert(tuple(nulls))
 
     def cardinality(self):
-        """Devuelve la cantidad de filas de la relación"""
-
+        """Devuelve la cantidad de filas de la relación."""
         return len(self.content)
 
     def degree(self):
-        """Devuelve el grado de la relación"""
-
+        """Devuelve el grado de la relación."""
         return len(self._header)
 
     def project(self, *args):
-        """
-        The project operator returns a new relation.
+        """Return a new relation.
+
         Extract columns (attributes) resulting in a vertical subset of
         attributes of the relation
         """
-
         indexes = []
         for arg in args:
             try:
                 indexes.append(self._header.index(arg))
             except ValueError as reason:
-                raise FieldNotInHeaderError(str(reason).split()[0], self.name)
+                raise FieldNotInHeaderError(str(reason).split()[0], self.name) from None
         # New fields
         header = [self._header[i] for i in indexes]
         # New relation
@@ -177,11 +176,10 @@ def project(self, *args):
         return new_relation
 
     def select(self, expression):
-        """
-        The select operator returns a new relation with the tuples that
-        satisfy an expression.
-        """
+        """Return a new relation.
 
+        with the tuples thatsatisfy an expression.
+        """
         new_relation = Relation()
         new_relation.header = self._header
 
@@ -254,11 +252,11 @@ def fouter(self, other_relation):
 
     @union_compatible
     def union(self, other_relation):
-        """
-        The union is defined as: R ∪ S. Returns the set of tuples in R,
+        """R U S.
+
+        Returns the set of tuples in R,
         or S, or both. R and S must be compatible unions.
         """
-
         new_relation = Relation()
         new_relation.header = self._header
         content = self.content.union(other_relation.content)
@@ -270,11 +268,11 @@ def union(self, other_relation):
 
     @union_compatible
     def difference(self, other_relation):
-        """
-        The difference is defined as: R - S. It is the set of all tuples
+        """R - S.
+
+        It is the set of all tuples
         in R, but not in S. R and S must be compatible unions
         """
-
         new_relation = Relation()
         new_relation.header = self._header
         content = self.content - other_relation.content
@@ -284,11 +282,11 @@ def difference(self, other_relation):
 
     @union_compatible
     def intersect(self, other_relation):
-        """
-        The intersection is defined as: R ∩ S. corresponds to the set of
+        """R ∩ S.
+
+        Corresponds to the set of
         all tuples in R and S, R and S compatible unions.
         """
-
         new_relation = Relation()
         new_relation.header = self._header
         content = self.content.intersection(other_relation.content)
@@ -299,14 +297,14 @@ def intersect(self, other_relation):
         return new_relation
 
     def product(self, other_relation):
-        """
-        The cartesian product is defined as: R x S, its outline
+        """R x S.
+
+        its outline
         corresponds to a combination of all tuples in R with each S
         tuples, and attributes corresponding to those of R followed by S.
 
         This method throws an exception when you are duplicate field names
         """
-
         for field in self._header:
             if field in other_relation.header:
                 raise DuplicateFieldError(field)
@@ -321,8 +319,6 @@ def product(self, other_relation):
         return new_relation
 
     def __str__(self):
-        """Magic method. Returns a representation of the relation"""
-
         header = ""
         for field in self._header:
             header += "|  " + field.center(10) + "  "
diff --git a/src/pireal/gui/__init__.py b/src/pireal/gui/__init__.py
index f916ce5..d579114 100644
--- a/src/pireal/gui/__init__.py
+++ b/src/pireal/gui/__init__.py
@@ -17,10 +17,6 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-"""
-Metadata
-"""
-
 __author__ = "Gabriel Acosta"
 __email__ = "acostadariogabriel at gmail"
 __source_code__ = "https://github.com/centaurialpha/pireal"
diff --git a/src/pireal/gui/central_widget.py b/src/pireal/gui/central_widget.py
index 2376a98..0d1694b 100644
--- a/src/pireal/gui/central_widget.py
+++ b/src/pireal/gui/central_widget.py
@@ -17,40 +17,32 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-import os
 import csv
 import logging
-from pathlib import Path
+import os
 from collections import defaultdict
+from pathlib import Path
 
-from PyQt6.QtWidgets import QWidget
-from PyQt6.QtWidgets import QVBoxLayout
-from PyQt6.QtWidgets import QStackedWidget
-from PyQt6.QtWidgets import QFileDialog
-from PyQt6.QtWidgets import QMessageBox
-from PyQt6.QtGui import QShortcut
-
-from PyQt6.QtGui import QKeySequence
-from PyQt6.QtCore import Qt
-from PyQt6.QtCore import QSettings
+from PyQt6.QtCore import QSettings, Qt
+from PyQt6.QtGui import QKeySequence, QShortcut
+from PyQt6.QtWidgets import (
+    QFileDialog,
+    QMessageBox,
+    QStackedWidget,
+    QVBoxLayout,
+    QWidget,
+)
 
 import pireal
-from pireal.dirs import EXAMPLE_DB_FILENAME
 from pireal import settings
-from pireal.core import (
-    file_manager,
-    pfile,
-)
+from pireal import translations as tr
+from pireal.core import file_manager, pfile
+from pireal.dirs import DATA_SETTINGS, EXAMPLE_DB_FILENAME
 from pireal.gui import start_page
 from pireal.gui.database_container import DatabaseContainer
-from pireal.gui.dialogs import (
-    preferences,
-    new_relation_dialog,
-)
+from pireal.gui.dialogs import new_relation_dialog, preferences
 from pireal.gui.dialogs.new_database_dialog import DBInputDialog
 from pireal.gui.lateral_widget import RelationItemType
-from pireal.dirs import DATA_SETTINGS
-from pireal import translations as tr
 
 # Logger
 logger = logging.getLogger(__name__)
@@ -117,8 +109,8 @@ def rdb_container_to_pdb_container(self):
 
     def create_database(self):
         """Show a wizard widget to create a new database,
-        only have one database open at time."""
-
+        only have one database open at time.
+        """
         if self.created:
             return self.__say_about_one_db_container_at_time()
         db_container_filepath = DBInputDialog.ask_db_name(parent=self)
@@ -248,11 +240,9 @@ def save_query_as(self):
         db_container.save_query_as()
 
     def __sanitize_data(self, data):
-        """
-        Este método convierte el contenido de la base de datos a un
+        """Este método convierte el contenido de la base de datos a un
         diccionario para un mejor manejo despues
         """
-
         # FIXME: controlar cuando al final de la línea hay una coma
         data_dict = defaultdict(list)
         for line_count, line in enumerate(data.splitlines()):
@@ -281,7 +271,6 @@ def __sanitize_data(self, data):
 
     def remove_last_widget(self):
         """Remove last widget from stacked"""
-
         widget = self.stack.widget(self.stack.count() - 1)
         self.stack.removeWidget(widget)
 
@@ -295,7 +284,6 @@ def close_query(self):
 
     def close_database(self) -> None:
         """Close the database and return to the main widget"""
-
         pireal_instance = pireal.get_pireal_instance()
         db_container = pireal_instance.db_container
         if db_container is None:
@@ -450,7 +438,6 @@ def _create_relation(relation, relation_name):
 
     def load_relation(self, filename=""):
         """Load Relation file"""
-
         filenames = []
         if not filename:
             if self._last_open_folder is None:
@@ -478,24 +465,20 @@ def load_relation(self, filename=""):
 
     def add_start_page(self):
         """This function adds the Start Page to the stacked widget"""
-
         sp = start_page.StartPage()
         self.add_widget(sp)
 
     def show_settings(self):
         """Show settings dialog on stacked"""
-
         settings_dialog = preferences.SettingsDialog(self)
         settings_dialog.exec()
 
     def widget(self, index):
         """Returns the widget at the given index"""
-
         return self.stack.widget(index)
 
     def add_widget(self, widget):
         """Appends and show the given widget to the Stacked"""
-
         index = self.stack.addWidget(widget)
         self.stack.setCurrentIndex(index)
 
diff --git a/src/pireal/gui/database_container.py b/src/pireal/gui/database_container.py
index e1cd829..b7e08c4 100644
--- a/src/pireal/gui/database_container.py
+++ b/src/pireal/gui/database_container.py
@@ -20,28 +20,19 @@
 import csv
 import logging
 
-from PyQt6.QtWidgets import QSplitter
-from PyQt6.QtWidgets import QFileDialog
-from PyQt6.QtWidgets import QMessageBox
-
-from PyQt6.QtCore import Qt
-from PyQt6.QtCore import QSettings
+from PyQt6.QtCore import QSettings, Qt
 from PyQt6.QtCore import pyqtSlot as Slot
+from PyQt6.QtWidgets import QFileDialog, QMessageBox, QSplitter
 
-from pireal.gui.lateral_widget import LateralWidget
-from pireal.gui.table_widget import TableWidget
-from pireal.gui.model_view_delegate import create_view
-from pireal.gui.lateral_widget import RelationItemType
-
-from pireal.gui.query_container.query_container import (
-    QueryContainer,
-    QueryWidget,
-)
 import pireal
-from pireal.core import relation, pfile, file_manager
-from pireal.dirs import DATA_SETTINGS
-from pireal import translations as tr
 from pireal import settings
+from pireal import translations as tr
+from pireal.core import file_manager, pfile, relation
+from pireal.dirs import DATA_SETTINGS
+from pireal.gui.lateral_widget import LateralWidget, RelationItemType
+from pireal.gui.model_view_delegate import create_view
+from pireal.gui.query_container.query_container import QueryContainer, QueryWidget
+from pireal.gui.table_widget import TableWidget
 
 logger = logging.getLogger(__name__)
 
@@ -88,7 +79,6 @@ def _on_relation_clicked(self, index):
 
     def dbname(self):
         """Return display name"""
-
         return self.pfile.display_name
 
     def is_new(self):
@@ -120,7 +110,6 @@ def create_database(self, data):
 
     def create_table(self, relation_obj, relation_name, editable=True):
         """Se crea la vista, el model y el delegado para @relation_obj"""
-
         return create_view(relation_obj, editable=editable)
 
     @Slot(bool)
@@ -257,7 +246,6 @@ def showEvent(self, event):
 
     def save_sizes(self):
         """Save sizes of Splitters"""
-
         qsettings = QSettings(str(DATA_SETTINGS), QSettings.Format.IniFormat)
         qsettings.setValue("vsplitter_sizes", self._vsplitter.saveState())
         qsettings.setValue("hsplitter_sizes", self.saveState())
diff --git a/src/pireal/gui/dialogs/about_dialog.py b/src/pireal/gui/dialogs/about_dialog.py
index 6c7c05e..2b16c61 100644
--- a/src/pireal/gui/dialogs/about_dialog.py
+++ b/src/pireal/gui/dialogs/about_dialog.py
@@ -19,17 +19,18 @@
 
 from datetime import datetime
 
+from PyQt6.QtCore import Qt
+from PyQt6.QtGui import QPixmap
 from PyQt6.QtWidgets import (
     QDialog,
-    QVBoxLayout,
-    QLabel,
     QHBoxLayout,
-    QSpacerItem,
-    QSizePolicy,
+    QLabel,
     QPushButton,
+    QSizePolicy,
+    QSpacerItem,
+    QVBoxLayout,
 )
-from PyQt6.QtGui import QPixmap
-from PyQt6.QtCore import Qt
+
 from pireal import __version__, gui
 from pireal import translations as tr
 
diff --git a/src/pireal/gui/dialogs/edit_relation_dialog.py b/src/pireal/gui/dialogs/edit_relation_dialog.py
index 0602c02..d89301f 100644
--- a/src/pireal/gui/dialogs/edit_relation_dialog.py
+++ b/src/pireal/gui/dialogs/edit_relation_dialog.py
@@ -17,18 +17,18 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-from PyQt6.QtWidgets import QDialog
-from PyQt6.QtWidgets import QVBoxLayout
-from PyQt6.QtWidgets import QHBoxLayout
-from PyQt6.QtWidgets import QPlainTextEdit
-from PyQt6.QtWidgets import QLabel
-from PyQt6.QtWidgets import QPushButton
-from PyQt6.QtWidgets import QStyle
-from PyQt6.QtWidgets import QMessageBox
-
-from PyQt6.QtGui import QFont
-
 from PyQt6.QtCore import pyqtSignal
+from PyQt6.QtGui import QFont
+from PyQt6.QtWidgets import (
+    QDialog,
+    QHBoxLayout,
+    QLabel,
+    QMessageBox,
+    QPlainTextEdit,
+    QPushButton,
+    QStyle,
+    QVBoxLayout,
+)
 
 from pireal.gui.main_window import Pireal
 from pireal.settings import CONFIG
diff --git a/src/pireal/gui/dialogs/new_database_dialog.py b/src/pireal/gui/dialogs/new_database_dialog.py
index 7934ff9..00988a8 100644
--- a/src/pireal/gui/dialogs/new_database_dialog.py
+++ b/src/pireal/gui/dialogs/new_database_dialog.py
@@ -19,18 +19,19 @@
 
 import os
 
-from PyQt6.QtWidgets import QDialog
-from PyQt6.QtWidgets import QDialogButtonBox
-from PyQt6.QtWidgets import QFormLayout
-from PyQt6.QtWidgets import QLineEdit
-from PyQt6.QtWidgets import QStyle
-from PyQt6.QtWidgets import QFileDialog
-
-from PyQt6.QtCore import pyqtSlot as Slot
 from PyQt6.QtCore import Qt
+from PyQt6.QtCore import pyqtSlot as Slot
+from PyQt6.QtWidgets import (
+    QDialog,
+    QDialogButtonBox,
+    QFileDialog,
+    QFormLayout,
+    QLineEdit,
+    QStyle,
+)
 
-from pireal import translations as tr
 from pireal import dirs
+from pireal import translations as tr
 
 PIREAL_DB_EXTENSION = ".pdb"
 
diff --git a/src/pireal/gui/dialogs/new_relation_dialog.py b/src/pireal/gui/dialogs/new_relation_dialog.py
index c3a14f8..3b8a910 100644
--- a/src/pireal/gui/dialogs/new_relation_dialog.py
+++ b/src/pireal/gui/dialogs/new_relation_dialog.py
@@ -17,25 +17,24 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
+from PyQt6.QtCore import Qt
+from PyQt6.QtCore import pyqtSignal as Signal
+from PyQt6.QtGui import QStandardItemModel
 from PyQt6.QtWidgets import (
-    QMessageBox,
     QDialog,
-    QVBoxLayout,
     QHBoxLayout,
     QLineEdit,
+    QMessageBox,
     QPushButton,
-    QSpacerItem,
     QSizePolicy,
+    QSpacerItem,
+    QVBoxLayout,
 )
-from PyQt6.QtGui import QStandardItemModel
-from PyQt6.QtCore import Qt
-from PyQt6.QtCore import pyqtSignal as Signal
 
 import pireal
-from pireal.core import relation
-from pireal.gui.model_view_delegate import View, Header
-
 from pireal import translations as tr
+from pireal.core import relation
+from pireal.gui.model_view_delegate import Header, View
 
 
 class NewRelationDialog(QDialog):
@@ -91,7 +90,6 @@ def __init__(self, parent=None):
 
     def __add_tuple(self):
         """Agrega una tupla/fila al final de la tabla"""
-
         model = self._view.model()
         model.insertRow(model.rowCount())
 
diff --git a/src/pireal/gui/dialogs/preferences.py b/src/pireal/gui/dialogs/preferences.py
index 4a5405a..318af02 100644
--- a/src/pireal/gui/dialogs/preferences.py
+++ b/src/pireal/gui/dialogs/preferences.py
@@ -17,23 +17,23 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-from PyQt6.QtWidgets import QDialog
-from PyQt6.QtWidgets import QVBoxLayout
-from PyQt6.QtWidgets import QGridLayout
-from PyQt6.QtWidgets import QLabel
-from PyQt6.QtWidgets import QComboBox
-from PyQt6.QtWidgets import QFontComboBox
-from PyQt6.QtWidgets import QCheckBox
-from PyQt6.QtWidgets import QGroupBox
-from PyQt6.QtWidgets import QDialogButtonBox
-
-from PyQt6.QtGui import QFontDatabase
-
 from PyQt6.QtCore import Qt
+from PyQt6.QtGui import QFontDatabase
+from PyQt6.QtWidgets import (
+    QCheckBox,
+    QComboBox,
+    QDialog,
+    QDialogButtonBox,
+    QFontComboBox,
+    QGridLayout,
+    QGroupBox,
+    QLabel,
+    QVBoxLayout,
+)
 
 import pireal
-from pireal.settings import SETTINGS
 from pireal import translations as tr
+from pireal.settings import SETTINGS
 
 
 class SettingsDialog(QDialog):
diff --git a/src/pireal/gui/lateral_widget.py b/src/pireal/gui/lateral_widget.py
index 8ea70ca..d58ba7a 100644
--- a/src/pireal/gui/lateral_widget.py
+++ b/src/pireal/gui/lateral_widget.py
@@ -20,23 +20,29 @@
 import enum
 from collections import namedtuple
 
-from PyQt6.QtWidgets import QListView
-from PyQt6.QtWidgets import QVBoxLayout
-from PyQt6.QtWidgets import QFrame
-from PyQt6.QtWidgets import QLabel
-from PyQt6.QtWidgets import QSplitter
-from PyQt6.QtWidgets import QStyledItemDelegate
-from PyQt6.QtWidgets import QStyleOptionViewItem
-from PyQt6.QtWidgets import QStyle
-from PyQt6.QtWidgets import QSizePolicy
-
-from PyQt6.QtCore import Qt, QRect, QModelIndex
-from PyQt6.QtCore import QAbstractListModel
-from PyQt6.QtCore import pyqtSignal as Signal
+from PyQt6.QtCore import (
+    QAbstractListModel,
+    QModelIndex,
+    QRect,
+    Qt,
+)
+from PyQt6.QtCore import (
+    pyqtSignal as Signal,
+)
+from PyQt6.QtWidgets import (
+    QFrame,
+    QLabel,
+    QListView,
+    QSizePolicy,
+    QSplitter,
+    QStyle,
+    QStyledItemDelegate,
+    QStyleOptionViewItem,
+    QVBoxLayout,
+)
 
 from pireal import translations as tr
 
-
 RelationItem = namedtuple("RelationItem", "name cardinality degree")
 
 
@@ -176,8 +182,7 @@ def __init__(self, header_text="", parent=None):
 
 
 class LateralWidget(QSplitter):
-    """
-    Widget que contiene la lista de relaciones y la lista de relaciones
+    """Widget que contiene la lista de relaciones y la lista de relaciones
     del resultado de consultas
     """
 
diff --git a/src/pireal/gui/main_window.py b/src/pireal/gui/main_window.py
index 13f2d81..fa7049c 100644
--- a/src/pireal/gui/main_window.py
+++ b/src/pireal/gui/main_window.py
@@ -17,50 +17,49 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-""" Pireal Main Window """
+"""Pireal Main Window."""
 
 import webbrowser
 
-from PyQt6.QtWidgets import (
-    QMainWindow,
-    QMessageBox,
-    QSystemTrayIcon,
-    QFrame,
-    QGridLayout,
-    QLabel,
-    QToolButton,
-    QHBoxLayout,
-    QApplication,
-)
-from PyQt6.QtGui import QIcon
-
 from PyQt6.QtCore import (
     QSettings,
-    QThread,
     Qt,
+    QThread,
     QTimer,
-    pyqtSlot as Slot,
+)
+from PyQt6.QtCore import (
     pyqtSignal as Signal,
 )
+from PyQt6.QtCore import (
+    pyqtSlot as Slot,
+)
+from PyQt6.QtGui import QIcon
+from PyQt6.QtWidgets import (
+    QApplication,
+    QFrame,
+    QGridLayout,
+    QHBoxLayout,
+    QLabel,
+    QMainWindow,
+    QMessageBox,
+    QSystemTrayIcon,
+    QToolButton,
+)
 
 import pireal
-from pireal import keymap
+from pireal import __version__, keymap
+from pireal import translations as tr
+from pireal.dirs import DATA_SETTINGS
+from pireal.gui import menu_actions
 from pireal.gui.central_widget import CentralWidget
 from pireal.gui.database_container import DatabaseContainer
+from pireal.gui.theme import apply_theme
 from pireal.gui.updater import Updater
-from pireal.gui import (
-    menu_actions,
-)
-
 from pireal.settings import SETTINGS
-from pireal.gui.theme import apply_theme
-from pireal import __version__
-from pireal.dirs import DATA_SETTINGS
-from pireal import translations as tr
 
 
 class _StatusBar(QFrame):
-    """Status bar divide in three areas"""
+    """Status bar divide in three areas."""
 
     playClicked = Signal()
     gearClicked = Signal()
@@ -145,9 +144,7 @@ def update_line_and_col(self, line, col):
 
 
 class Pireal(QMainWindow):
-
-    """
-    Main Window class
+    """Main Window class.
 
     This class is responsible for installing all application services.
     """
@@ -247,10 +244,6 @@ def open_download_release(self):
         webbrowser.open_new("https://github.com/centaurialpha/pireal/releases/latest")
 
     def __load_menubar(self, menubar):
-        """
-        This method installs the menubar and toolbar, menus and QAction's,
-        also connects to a slot each QAction.
-        """
         menu_bar = self.menuBar()
 
         for menu in menu_actions.MENU:
@@ -300,26 +293,22 @@ def change_title(self, title=""):
         self.setWindowTitle(_title)
 
     def about_qt(self):
-        """Show about qt dialog"""
-
+        """Show about qt dialog."""
         QMessageBox.aboutQt(self)
 
     def about_pireal(self):
-        """Show the bout Pireal dialog"""
-
+        """Show the bout Pireal dialog."""
         from pireal.gui.dialogs import about_dialog
 
         dialog = about_dialog.AboutDialog(self)
         dialog.exec()
 
     def report_issue(self):
-        """Open in the browser the page to create new  issue"""
-
+        """Open in the browser the page to create new issue."""
         webbrowser.open("http://github.com/centaurialpha/pireal/issues/new")
 
     def show_hide_menubar(self):
-        """Change visibility of menu bar"""
-
+        """Change visibility of menu bar."""
         if self.menuBar().isVisible():
             self.menuBar().hide()
         else:
diff --git a/src/pireal/gui/menu_actions.py b/src/pireal/gui/menu_actions.py
index 779dfca..ee3c9ec 100644
--- a/src/pireal/gui/menu_actions.py
+++ b/src/pireal/gui/menu_actions.py
@@ -17,8 +17,7 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-"""
-This module contains an ordered dictionary, in turn this has a dictionary
+"""This module contains an ordered dictionary, in turn this has a dictionary
 with the name and a list of items with properties as an icon , shortcut,
 slot for each item in a menu.
 
diff --git a/src/pireal/gui/model_view_delegate.py b/src/pireal/gui/model_view_delegate.py
index 12e2b3d..62e8a38 100644
--- a/src/pireal/gui/model_view_delegate.py
+++ b/src/pireal/gui/model_view_delegate.py
@@ -19,20 +19,18 @@
 
 import logging
 
-from PyQt6.QtWidgets import QTableView
-from PyQt6.QtWidgets import QHeaderView
-from PyQt6.QtWidgets import QAbstractItemView
-from PyQt6.QtWidgets import QItemDelegate
-from PyQt6.QtWidgets import QInputDialog
-
+from PyQt6.QtCore import QAbstractTableModel, QModelIndex, Qt
+from PyQt6.QtCore import pyqtSlot as Slot
 from PyQt6.QtGui import QColor
+from PyQt6.QtWidgets import (
+    QAbstractItemView,
+    QHeaderView,
+    QInputDialog,
+    QItemDelegate,
+    QTableView,
+)
 
-from PyQt6.QtCore import QAbstractTableModel
-from PyQt6.QtCore import Qt
-from PyQt6.QtCore import QModelIndex
-from PyQt6.QtCore import pyqtSlot as Slot
 from pireal import translations as tr
-
 from pireal.gui.theme import get_color
 
 logger = logging.getLogger("gui.model_view_delegate")
@@ -126,7 +124,6 @@ def resizeEvent(self, event):
 
     def adjust_columns(self):
         """Resize all sections to content and user interactive"""
-
         header = self.horizontalHeader()
         for column in range(header.count()):
             header.setSectionResizeMode(column, QHeaderView.ResizeMode.ResizeToContents)
diff --git a/src/pireal/gui/query_container/editor.py b/src/pireal/gui/query_container/editor.py
index 6dcadf5..de4bbd3 100644
--- a/src/pireal/gui/query_container/editor.py
+++ b/src/pireal/gui/query_container/editor.py
@@ -17,22 +17,21 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
+from PyQt6.QtCore import Qt, QTimer
+from PyQt6.QtGui import QColor, QFont, QTextCharFormat, QTextCursor, QTextDocument
 from PyQt6.QtWidgets import (
-    QPlainTextEdit,
-    QTextEdit,
     QFrame,
-    QLabel,
     QHBoxLayout,
+    QLabel,
+    QPlainTextEdit,
+    QTextEdit,
     QToolButton,
 )
-from PyQt6.QtGui import QTextCharFormat, QTextCursor, QFont, QColor, QTextDocument
-from PyQt6.QtCore import Qt, QTimer
 
 from pireal.gui.query_container import highlighter, sidebar
 from pireal.gui.theme import get_editor_color
 from pireal.settings import SETTINGS
 
-
 BRACKETS = "()"
 OPOSITE_BRACKET = {
     "(": ")",
@@ -206,7 +205,6 @@ def filename(self):
 
         :returns: filename of PFile
         """
-
         return self.pfile.filename
 
     @property
@@ -228,7 +226,8 @@ def paintEvent(self, event):
 
     def word_under_cursor(self, cursor=None):
         """Returns QTextCursor that contains a word under passed cursor
-        or actual cursor"""
+        or actual cursor
+        """
         if cursor is None:
             cursor = self.textCursor()
         start_pos = end_pos = cursor.position()
@@ -312,7 +311,6 @@ def zoom_out(self):
 
     def show_run_cursor(self):
         """Highlight momentarily a piece of code. Tomado de Ninja-IDE"""
-
         cursor = self.textCursor()
         if cursor.hasSelection():
             # Get selection range
@@ -342,7 +340,6 @@ def saved(self):
 
     def comment(self):
         """Comment one or more lines"""
-
         tcursor = self.textCursor()
         block_start = self.document().findBlock(tcursor.selectionStart())
         block_end = self.document().findBlock(tcursor.selectionEnd()).next()
@@ -360,7 +357,6 @@ def comment(self):
 
     def uncomment(self):
         """Uncomment one or more lines"""
-
         tcursor = self.textCursor()
         block_start = self.document().findBlock(tcursor.selectionStart())
         block_end = self.document().findBlock(tcursor.selectionEnd()).next()
diff --git a/src/pireal/gui/query_container/highlighter.py b/src/pireal/gui/query_container/highlighter.py
index c45c729..9643299 100644
--- a/src/pireal/gui/query_container/highlighter.py
+++ b/src/pireal/gui/query_container/highlighter.py
@@ -17,14 +17,14 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
+from PyQt6.QtCore import QRegularExpression
 from PyQt6.QtGui import (
-    QSyntaxHighlighter,
-    QTextCharFormat,
+    QColor,
     QFont,
+    QSyntaxHighlighter,
     QTextBlockUserData,
-    QColor,
+    QTextCharFormat,
 )
-from PyQt6.QtCore import QRegularExpression
 
 from pireal.gui.theme import get_editor_color
 
@@ -105,7 +105,6 @@ def __init__(self, editor):
 
     def highlightBlock(self, text):
         """Reimplementation"""
-
         block_data = TextBlockData()
         # Paren
         # index = self.paren.indexIn(text, 0)
diff --git a/src/pireal/gui/query_container/query_container.py b/src/pireal/gui/query_container/query_container.py
index dc80092..5e200cc 100644
--- a/src/pireal/gui/query_container/query_container.py
+++ b/src/pireal/gui/query_container/query_container.py
@@ -19,37 +19,34 @@
 
 import re
 
-from PyQt6.QtWidgets import QWidget
-from PyQt6.QtWidgets import QVBoxLayout
-from PyQt6.QtWidgets import QHBoxLayout
-from PyQt6.QtWidgets import QSplitter
-from PyQt6.QtWidgets import QStackedWidget
-from PyQt6.QtWidgets import QDialog
-from PyQt6.QtWidgets import QPushButton
-from PyQt6.QtWidgets import QLineEdit
-
-from PyQt6.QtCore import Qt
-from PyQt6.QtCore import QSettings
-
+from PyQt6.QtCore import QSettings, Qt
 from PyQt6.QtCore import pyqtSignal as Signal
+from PyQt6.QtWidgets import (
+    QDialog,
+    QHBoxLayout,
+    QLineEdit,
+    QPushButton,
+    QSplitter,
+    QStackedWidget,
+    QVBoxLayout,
+    QWidget,
+)
 
 import pireal
+from pireal import translations as tr
+from pireal.dirs import DATA_SETTINGS
+from pireal.gui.lateral_widget import RelationItemType
+
+# from pireal.gui.main_window import Pireal
+from pireal.gui.query_container import editor, tab_widget
 from pireal.interpreter import parser
 from pireal.interpreter.exceptions import (
+    ConsumeError,
+    DuplicateRelationNameError,
     InvalidSyntaxError,
     MissingQuoteError,
-    DuplicateRelationNameError,
-    ConsumeError,
 )
 
-# from pireal.gui.main_window import Pireal
-from pireal.gui.query_container import editor
-from pireal.gui.query_container import tab_widget
-from pireal.gui.lateral_widget import RelationItemType
-
-from pireal import translations as tr
-from pireal.dirs import DATA_SETTINGS
-
 
 class QueryContainer(QWidget):
     saveEditor = Signal(object)
@@ -86,14 +83,11 @@ def set_focus_editor_tab(self, index):
 
     def current_index(self):
         """This property holds the index position of the current tab page"""
-
         return self._tabs.currentIndex()
 
     def tab_text(self, index):
+        """Returns the label text for the tab on the page at position index
         """
-        Returns the label text for the tab on the page at position index
-        """
-
         return self._tabs.tabText(index)
 
     def __hide(self):
@@ -149,7 +143,6 @@ def __on_save_editor(self, editor):
 
     def execute_queries(self, query=""):
         """This function executes queries"""
-
         # If text is selected, then this text is the query,
         # otherwise the query is all text that has the editor
         editor_widget = self.currentWidget().get_editor()
@@ -227,7 +220,6 @@ def _highlight_error_in_editor(self, line_error, col=-1):
     @staticmethod
     def parse_error(text):
         """Replaces quotes by <b></b> tag"""
-
         return re.sub(r"\'(.*?)\'", r"<b>\1</b>", text)
 
     def __add_table(self, rela, rname):
@@ -338,7 +330,6 @@ def show_relation(self, item):
 
     def save_sizes(self):
         """Save sizes of Splitters"""
-
         qsettings = QSettings(str(DATA_SETTINGS), QSettings.IniFormat)
         qsettings.setValue(
             "result_splitter_query_sizes", self.result_splitter.saveState()
diff --git a/src/pireal/gui/query_container/sidebar.py b/src/pireal/gui/query_container/sidebar.py
index 440c4c8..11ace82 100644
--- a/src/pireal/gui/query_container/sidebar.py
+++ b/src/pireal/gui/query_container/sidebar.py
@@ -17,22 +17,15 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-"""
-Sidebar widget with line numbers
+"""Sidebar widget with line numbers.
 
 based on:
 john.nachtimwald.com/2009/08/19/better-qplaintextedit-with-line-numbers/
 """
 
+from PyQt6.QtCore import QSize, Qt
+from PyQt6.QtGui import QColor, QFontMetrics, QPainter, QPen
 from PyQt6.QtWidgets import QFrame
-from PyQt6.QtGui import (
-    QFontMetrics,
-    QPainter,
-    QPen,
-    QColor,
-)
-from PyQt6.QtCore import Qt
-from PyQt6.QtCore import QSize
 
 from pireal.gui.theme import get_editor_color
 
@@ -79,7 +72,6 @@ def paintEvent(self, event):
 
         :param event: QEvent
         """
-
         painter = QPainter(self)
         painter.fillRect(event.rect(), self._background_color)
         width = self.width() - 8
diff --git a/src/pireal/gui/query_container/tab_widget.py b/src/pireal/gui/query_container/tab_widget.py
index 12d31f3..ec54782 100644
--- a/src/pireal/gui/query_container/tab_widget.py
+++ b/src/pireal/gui/query_container/tab_widget.py
@@ -17,8 +17,8 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-from PyQt6.QtWidgets import QTabWidget, QMessageBox
 from PyQt6.QtCore import pyqtSignal as Signal
+from PyQt6.QtWidgets import QMessageBox, QTabWidget
 
 
 class TabWidget(QTabWidget):
diff --git a/src/pireal/gui/start_page.py b/src/pireal/gui/start_page.py
index 0f7237e..12635ab 100644
--- a/src/pireal/gui/start_page.py
+++ b/src/pireal/gui/start_page.py
@@ -21,39 +21,35 @@
 import os
 from datetime import datetime
 
+from PyQt6.QtCore import (
+    QAbstractListModel,
+    QModelIndex,
+    QRect,
+    QSettings,
+    Qt,
+    QTimer,
+)
+from PyQt6.QtCore import (
+    pyqtSlot as Slot,
+)
+from PyQt6.QtGui import QPixmap
 from PyQt6.QtWidgets import (
-    QWidget,
-    QLabel,
     QFrame,
-    QPushButton,
-    QVBoxLayout,
     QHBoxLayout,
+    QLabel,
     QListView,
+    QPushButton,
     QSizePolicy,
+    QStyle,
     QStyledItemDelegate,
     QStyleOptionViewItem,
-    QStyle,
-)
-from PyQt6.QtGui import (
-    QPixmap,
-)
-from PyQt6.QtCore import (
-    QAbstractListModel,
-    Qt,
-    QRect,
-    QModelIndex,
-    QSettings,
-    QTimer,
-    pyqtSlot as Slot,
+    QVBoxLayout,
+    QWidget,
 )
 
 import pireal
-
-from pireal.dirs import (
-    DATA_SETTINGS,
-    EXAMPLES_DIR,
-)
 from pireal import translations as tr
+from pireal.dirs import DATA_SETTINGS, EXAMPLES_DIR
 
 logger = logging.getLogger(__name__)
 
@@ -80,7 +76,8 @@ def data(self, index, role=Qt.ItemDataRole.DisplayRole):
 
 class RecentDBDelegate(QStyledItemDelegate):
     """Custom delegate that show database name and database path
-    in same item"""
+    in same item
+    """
 
     def paint(self, painter, option, index):
         opt = QStyleOptionViewItem(option)
diff --git a/src/pireal/gui/table_widget.py b/src/pireal/gui/table_widget.py
index ba25756..10bf1c0 100644
--- a/src/pireal/gui/table_widget.py
+++ b/src/pireal/gui/table_widget.py
@@ -17,16 +17,11 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 
-from PyQt6.QtWidgets import QSplitter
-from PyQt6.QtWidgets import QTabWidget
-from PyQt6.QtWidgets import QToolButton
-from PyQt6.QtWidgets import QStackedWidget
-from PyQt6.QtWidgets import QMenu
-
 from PyQt6.QtCore import Qt
-from pireal.gui.model_view_delegate import create_view
+from PyQt6.QtWidgets import QMenu, QSplitter, QStackedWidget, QTabWidget, QToolButton
 
 from pireal import translations as tr
+from pireal.gui.model_view_delegate import create_view
 
 
 class TableWidget(QSplitter):
@@ -139,7 +134,6 @@ def add_relation(self, name, rela):
 
     def add_table(self, rela, name, table):
         """Add new table from New Relation Dialog"""
-
         self.add_relation(name, rela)
         self.stacked.addWidget(table)
 
@@ -174,7 +168,6 @@ def delete_tuple(self):
 
     def delete_column(self):
         """Elimina la/las columnas seleccionadas"""
-
         current_view = self.current_table()
         if current_view is not None:
             model = current_view.model()
@@ -193,5 +186,4 @@ def delete_column(self):
 
     def create_table(self, rela, editable=True):
         """Se crea la vista y el modelo"""
-
         return create_view(rela, editable=editable)
diff --git a/src/pireal/gui/theme.py b/src/pireal/gui/theme.py
index 6fd174f..f3d66f9 100644
--- a/src/pireal/gui/theme.py
+++ b/src/pireal/gui/theme.py
@@ -1,5 +1,4 @@
-from PyQt6.QtGui import QColor
-from PyQt6.QtGui import QPalette
+from PyQt6.QtGui import QColor, QPalette
 
 from pireal.settings import SETTINGS
 
diff --git a/src/pireal/gui/updater.py b/src/pireal/gui/updater.py
index 031d895..5099d0d 100644
--- a/src/pireal/gui/updater.py
+++ b/src/pireal/gui/updater.py
@@ -17,12 +17,12 @@
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 import logging
-
-from pkg_resources import parse_version
-from urllib.request import urlopen
 from urllib.error import URLError
+from urllib.request import urlopen
 
-from PyQt6.QtCore import QObject, pyqtSignal as Signal
+from pkg_resources import parse_version
+from PyQt6.QtCore import QObject
+from PyQt6.QtCore import pyqtSignal as Signal
 
 from pireal import __version__
 
diff --git a/src/pireal/interpreter/exceptions.py b/src/pireal/interpreter/exceptions.py
index aa4b324..2b8c8f8 100644
--- a/src/pireal/interpreter/exceptions.py
+++ b/src/pireal/interpreter/exceptions.py
@@ -22,11 +22,11 @@
 
 
 class InterpreterError(Exception):
-    """Excepción básica para errores generados por el intérprete"""
+    """Excepción básica para errores generados por el intérprete."""
 
 
 class MissingQuoteError(InterpreterError):
-    """Excepción para comillas faltantes en strings"""
+    """Excepción para comillas faltantes en strings."""
 
     def __init__(self, msg, lineno, col):
         InterpreterError.__init__(self, msg.format(lineno))
@@ -35,7 +35,7 @@ def __init__(self, msg, lineno, col):
 
 
 class InvalidSyntaxError(InterpreterError):
-    """Excepción para errores de sintáxis generados por el Lexer"""
+    """Excepción para errores de sintáxis generados por el Lexer."""
 
     def __init__(self, lineno, col, char, msg="Invalid syntax on '{0}':'{1}'"):
         InterpreterError.__init__(self, msg.format(lineno, col))
@@ -45,8 +45,6 @@ def __init__(self, lineno, col, char, msg="Invalid syntax on '{0}':'{1}'"):
 
 
 class ConsumeError(InterpreterError):
-    """Excepción para errores generados por el Parser cuando no se espera
-    un determinado símbolo del lenguaje"""
 
     def __init__(self, expected, got, lineno, msg=None):
         if msg is None:
@@ -61,8 +59,6 @@ def __init__(self, expected, got, lineno, msg=None):
 
 
 class DuplicateRelationNameError(InterpreterError):
-    """Excepción para errores generados por el Interpreter cuando se
-    usa un nombre que ya existe en el SCOPE"""
 
     def __init__(self, rname):
         super().__init__()
diff --git a/src/pireal/interpreter/lexer.py b/src/pireal/interpreter/lexer.py
index 992c5cb..5199fa2 100644
--- a/src/pireal/interpreter/lexer.py
+++ b/src/pireal/interpreter/lexer.py
@@ -20,21 +20,14 @@
 # This module is responsible for organizing called "tokens" pieces,
 # each of these tokens has a meaning in language
 
-from pireal.interpreter.tokens import (
-    Token,
-    TokenTypes,
-    RESERVED_KEYWORDS,
-)
+from pireal.interpreter.exceptions import InvalidSyntaxError, MissingQuoteError
 from pireal.interpreter.scanner import Scanner
-from pireal.interpreter.exceptions import MissingQuoteError, InvalidSyntaxError
-from pireal.interpreter.utils import (
-    is_date,
-    is_time,
-)
+from pireal.interpreter.tokens import RESERVED_KEYWORDS, Token, TokenTypes
+from pireal.interpreter.utils import is_date, is_time
 
 
 class Lexer:
-    """This is the first stage of analysis.
+    """First stage of analysis.
 
     The Lexer serves to break up the source text into chuncks, "tokens".
     It calls the Scanner to get characters one at a time and organizes them
@@ -68,8 +61,7 @@ def _skip_comment(self):
         self.sc.next()
 
     def get_identifier_or_keyword(self) -> Token:
-        """Handle identifiers and reserved keywords"""
-
+        """Handle identifiers and reserved keywords."""
         token = Token(
             type=TokenTypes.UNKNOWN, value=None, line=self.sc.lineno, col=self.sc.colno
         )
@@ -99,8 +91,7 @@ def get_identifier_or_keyword(self) -> Token:
         return token
 
     def get_number(self) -> Token:
-        """Returns a multidigit integer or float"""
-
+        """Return a multidigit integer or float."""
         token = Token(
             type=TokenTypes.UNKNOWN, value=None, line=self.sc.lineno, col=self.sc.colno
         )
@@ -166,7 +157,6 @@ def next_token(self) -> Token:
         This method is responsible for breaking a sentence apart
         into tokens. One token at a time
         """
-
         while self.sc.char is not None:
             # Recognize identifiers and keywords
             if self.sc.char.isalpha() or self.sc.char.startswith("_"):
@@ -241,7 +231,9 @@ def next_token(self) -> Token:
             try:
                 token_type = TokenTypes(self.sc.char)
             except ValueError:
-                raise InvalidSyntaxError(self.sc.lineno, self.sc.colno, self.sc.char)
+                raise InvalidSyntaxError(
+                    self.sc.lineno, self.sc.colno, self.sc.char
+                ) from None
             else:
                 token = Token(
                     type=token_type,
diff --git a/src/pireal/interpreter/parser.py b/src/pireal/interpreter/parser.py
index fa29698..7f14070 100644
--- a/src/pireal/interpreter/parser.py
+++ b/src/pireal/interpreter/parser.py
@@ -16,7 +16,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
-"""
+"""BNF.
+
 <Compound>          : <Query>
                     | <Query> <Compund>
 <Query>             : <Assignment> SEMI
@@ -59,20 +60,17 @@
                     | TIME
 """
 
-from pireal.interpreter.tokens import (
-    TokenTypes,
-    BINARY_OPERATORS,
-)
-from pireal.interpreter.exceptions import ConsumeError
-from pireal.interpreter.exceptions import DuplicateRelationNameError
-
-from pireal.interpreter.scanner import Scanner
-from pireal.interpreter.lexer import Lexer
 from pireal.interpreter import rast as ast
+from pireal.interpreter.exceptions import ConsumeError, DuplicateRelationNameError
+from pireal.interpreter.lexer import Lexer
+from pireal.interpreter.scanner import Scanner
+from pireal.interpreter.tokens import BINARY_OPERATORS, TokenTypes
 
 
 class Parser(object):
-    """The Parser is the part that really understands the syntax of
+    """The Parser.
+
+    Is the part that really understands the syntax of
     the language. It calls the Lexer to get tokens and processes the tokens
     per the syntax of the language.
     """
@@ -83,10 +81,10 @@ def __init__(self, lexer):
 
     def consume(self, token_type):
         """Consume a token of a given type and get the next token.
+
         If the current token is not of the expected type, then
         raise an error
         """
-
         if self.token.type == token_type:
             self.token = self.lexer.next_token()
         else:
@@ -240,7 +238,7 @@ def operator(self):
         return node
 
     def attributes(self):
-        """Return a list of ast.Variable nodes"""
+        """Return a list of ast.Variable nodes."""
         node = self.variable()
 
         attribute_list = [node]
@@ -252,7 +250,9 @@ def attributes(self):
 
 
 class Interpreter(ast.NodeVisitor):
-    """Este objeto es el encargado de 'visitar' los nodos con el
+    """Visitor.
+
+    Este objeto es el encargado de 'visitar' los nodos con el
     método Interpreter.to_python(), que convierte a un string que luego
     es evaluado como código Python
 
diff --git a/src/pireal/interpreter/rast.py b/src/pireal/interpreter/rast.py
index 70f449b..0d94a83 100644
--- a/src/pireal/interpreter/rast.py
+++ b/src/pireal/interpreter/rast.py
@@ -1,5 +1,5 @@
 class AST(object):
-    """Base class for all nodes"""
+    """Base class for all nodes."""
 
     def __eq__(self, other):
         attrs = [attr for attr in dir(self) if not attr.startswith("_")]
@@ -86,7 +86,7 @@ def __init__(self):
 
 
 class NodeVisitor(object):
-    """Visitor pattern
+    """Visitor pattern.
 
     A node visitor base class that walks the abstract syntax tree and calls
     a visitor function for every node found. This function may return a value
@@ -103,13 +103,11 @@ class NodeVisitor(object):
     """
 
     def visit(self, node):
-        """Visit a node"""
-
+        """Visit a node."""
         method_name = "visit_" + node.__class__.__name__
         visitor = getattr(self, method_name, self._generic_visit)
         return visitor(node)
 
     def _generic_visit(self, node):
-        """Called if not explicit visitor function exists for a node"""
-
-        raise Exception("No visit_{} method".format(node.__class__.__name__))
+        """Call if not explicit visitor function exists for a node."""
+        raise Exception(f"No visit_{node.__class__.__name__} method")
diff --git a/src/pireal/interpreter/scanner.py b/src/pireal/interpreter/scanner.py
index 402c86b..9b69dcc 100644
--- a/src/pireal/interpreter/scanner.py
+++ b/src/pireal/interpreter/scanner.py
@@ -21,8 +21,9 @@
 
 
 class Scanner:
-    """
-    The Scanner is used to step through text character by character
+    """The Scanner.
+
+    Is used to step through text character by character
     and keep track of the line and column number of each passed character
     """
 
@@ -36,8 +37,7 @@ def __init__(self, text: str):
 
     @property
     def char(self) -> str | None:
-        """Returns a character in the current index"""
-
+        """Return a character in the current index."""
         if self.index < len(self._text):
             return self._text[self.index]
 
@@ -51,8 +51,7 @@ def peek(self) -> str | None:
         return self._text[peek_pos]
 
     def next(self) -> None:
-        """Move on to the next character in the scanned text"""
-
+        """Move on to the next character in the scanned text."""
         if self.char == "\n":
             # We are in a new line, therefore we increase the line
             # number and restart the column number
@@ -63,8 +62,7 @@ def next(self) -> None:
         self.index += 1
 
     def next_char(self) -> str | None:
-        """Returns the next character in the source text"""
-
+        """Return the next character in the source text."""
         self.next()
         return self.char
 
diff --git a/src/pireal/interpreter/tokens.py b/src/pireal/interpreter/tokens.py
index 6e3c4bb..8a6e5be 100644
--- a/src/pireal/interpreter/tokens.py
+++ b/src/pireal/interpreter/tokens.py
@@ -18,8 +18,8 @@
 # along with Pireal; If not, see <http://www.gnu.org/licenses/>.
 from __future__ import annotations
 
-import enum
 import datetime
+import enum
 from dataclasses import dataclass