From 7a88dc9076390b2e539376f3a1b3afb0050b8821 Mon Sep 17 00:00:00 2001
From: Salvo 'LtWorf' Tomaselli <tiposchi@tiscali.it>
Date: Sun, 2 Jul 2017 12:50:48 +0200
Subject: [PATCH] Replace == None with is

---
 relational/parser.py         | 4 ++--
 relational_gui/creator.py    | 2 +-
 relational_gui/guihandler.py | 8 ++++----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/relational/parser.py b/relational/parser.py
index 22eb518..c09eb46 100644
--- a/relational/parser.py
+++ b/relational/parser.py
@@ -108,7 +108,7 @@ class Node:
     def __init__(self, expression: Optional[list] = None) -> None:
         '''Generates the tree from the tokenized expression
         If no expression is specified then it will create an empty node'''
-        if expression == None or len(expression) == 0:
+        if expression is None or len(expression) == 0:
             return
 
         # If the list contains only a list, it will consider the lower level list.
@@ -351,7 +351,7 @@ def tokenize(expression: str) -> list:
     while len(expression) > 0:
         if expression.startswith('('):  # Parenthesis state
             end = _find_matching_parenthesis(expression)
-            if end == None:
+            if end is None:
                 raise TokenizerException(
                     "Missing matching ')' in '%s'" % expression)
             # Appends the tokenization of the content of the parenthesis
diff --git a/relational_gui/creator.py b/relational_gui/creator.py
index b4e2f83..1da2e78 100644
--- a/relational_gui/creator.py
+++ b/relational_gui/creator.py
@@ -35,7 +35,7 @@ class creatorForm(QtWidgets.QDialog):
         self.ui = ui
         self.table = self.ui.table
 
-        if self.rel == None:
+        if self.rel is None:
             self.setup_empty()
         else:
             self.setup_relation(self.rel)
diff --git a/relational_gui/guihandler.py b/relational_gui/guihandler.py
index 80ff863..d6aff2c 100644
--- a/relational_gui/guihandler.py
+++ b/relational_gui/guihandler.py
@@ -239,7 +239,7 @@ class relForm(QtWidgets.QMainWindow):
         '''Shows the selected relation into the table'''
         self.ui.table.clear()
 
-        if rel == None:  # No relation to show
+        if rel is None:  # No relation to show
             self.ui.table.setColumnCount(1)
             self.ui.table.headerItem().setText(0, "Empty relation")
             return
@@ -347,7 +347,7 @@ class relForm(QtWidgets.QMainWindow):
         from relational_gui import creator
         result = creator.edit_relation()
 
-        if result == None:
+        if result is None:
             return
         name = self.promptRelationName()
 
@@ -383,7 +383,7 @@ class relForm(QtWidgets.QMainWindow):
             pass
 
     def showSurvey(self):
-        if self.Survey == None:
+        if self.Survey is None:
             self.Survey = surveyForm.surveyForm()
             ui = survey.Ui_Form()
             self.Survey.setUi(ui)
@@ -392,7 +392,7 @@ class relForm(QtWidgets.QMainWindow):
         self.Survey.show()
 
     def showAbout(self):
-        if self.About == None:
+        if self.About is None:
             self.About = QtWidgets.QDialog()
             ui = about.Ui_Dialog()
             ui.setupUi(self.About)