Welcome folks today in this post we will be creating a advanced notepad which supports crud operations and also various other advanced features in pyqt5 library which is useful creating gui applications in python. All the full source code of the application will be given below.
Get Started
In order to get started you need to install the following library by pip command as shown below
pip install pyqt5
After installing this library make an app.py file and copy paste the following code to it
app.py
# importing required libraries
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtPrintSupport import *
import os
import sys
# Creating main window class
class MainWindow(QMainWindow):
# constructor
def __init__(self, *args, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
# setting window geometry
self.setGeometry(100, 100, 600, 400)
# creating a layout
layout = QVBoxLayout()
# creating a QPlainTextEdit object
self.editor = QPlainTextEdit()
# setting font to the editor
fixedfont = QFontDatabase.systemFont(QFontDatabase.FixedFont)
fixedfont.setPointSize(12)
self.editor.setFont(fixedfont)
# self.path holds the path of the currently open file.
# If none, we haven't got a file open yet (or creating new).
self.path = None
# adding editor to the layout
layout.addWidget(self.editor)
# creating a QWidget layout
container = QWidget()
# setting layout to the container
container.setLayout(layout)
# making container as central widget
self.setCentralWidget(container)
# creating a status bar object
self.status = QStatusBar()
# setting stats bar to the winow
self.setStatusBar(self.status)
# creating a file tool bar
file_toolbar = QToolBar("File")
# adding file tool bar to the window
self.addToolBar(file_toolbar)
# creating a file menu
file_menu = self.menuBar().addMenu("&File")
# creating actions to add in the file menu
# creating a open file action
open_file_action = QAction("Open file", self)
# setting status tip
open_file_action.setStatusTip("Open file")
# adding action to the open file
open_file_action.triggered.connect(self.file_open)
# adding this to file menu
file_menu.addAction(open_file_action)
# adding this to tool bar
file_toolbar.addAction(open_file_action)
# similarly creating a save action
save_file_action = QAction("Save", self)
save_file_action.setStatusTip("Save current page")
save_file_action.triggered.connect(self.file_save)
file_menu.addAction(save_file_action)
file_toolbar.addAction(save_file_action)
# similarly creating save action
saveas_file_action = QAction("Save As", self)
saveas_file_action.setStatusTip("Save current page to specified file")
saveas_file_action.triggered.connect(self.file_saveas)
file_menu.addAction(saveas_file_action)
file_toolbar.addAction(saveas_file_action)
# for print action
print_action = QAction("Print", self)
print_action.setStatusTip("Print current page")
print_action.triggered.connect(self.file_print)
file_menu.addAction(print_action)
file_toolbar.addAction(print_action)
# creating another tool bar for editing text
edit_toolbar = QToolBar("Edit")
# adding this tool bar to the main window
self.addToolBar(edit_toolbar)
# creating a edit menu bar
edit_menu = self.menuBar().addMenu("&Edit")
# adding actions to the tool bar and menu bar
# undo action
undo_action = QAction("Undo", self)
# adding status tip
undo_action.setStatusTip("Undo last change")
# when triggered undo the editor
undo_action.triggered.connect(self.editor.undo)
# adding this to tool and menu bar
edit_toolbar.addAction(undo_action)
edit_menu.addAction(undo_action)
# redo action
redo_action = QAction("Redo", self)
redo_action.setStatusTip("Redo last change")
# when triggered redo the editor
redo_action.triggered.connect(self.editor.redo)
# adding this to menu and tool bar
edit_toolbar.addAction(redo_action)
edit_menu.addAction(redo_action)
# cut action
cut_action = QAction("Cut", self)
cut_action.setStatusTip("Cut selected text")
# when triggered cut the editor text
cut_action.triggered.connect(self.editor.cut)
# adding this to menu and tool bar
edit_toolbar.addAction(cut_action)
edit_menu.addAction(cut_action)
# copy action
copy_action = QAction("Copy", self)
copy_action.setStatusTip("Copy selected text")
# when triggered copy the editor text
copy_action.triggered.connect(self.editor.copy)
# adding this to menu and tool bar
edit_toolbar.addAction(copy_action)
edit_menu.addAction(copy_action)
# paste action
paste_action = QAction("Paste", self)
paste_action.setStatusTip("Paste from clipboard")
# when triggered paste the copied text
paste_action.triggered.connect(self.editor.paste)
# adding this to menu and tool bar
edit_toolbar.addAction(paste_action)
edit_menu.addAction(paste_action)
# select all action
select_action = QAction("Select all", self)
select_action.setStatusTip("Select all text")
# when this triggered select the whole text
select_action.triggered.connect(self.editor.selectAll)
# adding this to menu and tool bar
edit_toolbar.addAction(select_action)
edit_menu.addAction(select_action)
# wrap action
wrap_action = QAction("Wrap text to window", self)
wrap_action.setStatusTip("Check to wrap text to window")
# making it checkable
wrap_action.setCheckable(True)
# making it checked
wrap_action.setChecked(True)
# adding action
wrap_action.triggered.connect(self.edit_toggle_wrap)
# adding it to edit menu not to the tool bar
edit_menu.addAction(wrap_action)
# calling update title methpd
self.update_title()
# showing all the components
self.show()
# creating dialog critical method
# to show errors
def dialog_critical(self, s):
# creating a QMessageBox object
dlg = QMessageBox(self)
# setting text to the dlg
dlg.setText(s)
# setting icon to it
dlg.setIcon(QMessageBox.Critical)
# showing it
dlg.show()
# action called by file open action
def file_open(self):
# getting path and bool value
path, _ = QFileDialog.getOpenFileName(self, "Open file", "",
"Text documents (*.txt);All files (*.*)")
# if path is true
if path:
# try opening path
try:
with open(path, 'rU') as f:
# read the file
text = f.read()
# if some error occured
except Exception as e:
# show error using critical method
self.dialog_critical(str(e))
# else
else:
# update path value
self.path = path
# update the text
self.editor.setPlainText(text)
# update the title
self.update_title()
# action called by file save action
def file_save(self):
# if there is no save path
if self.path is None:
# call save as method
return self.file_saveas()
# else call save to path method
self._save_to_path(self.path)
# action called by save as action
def file_saveas(self):
# opening path
path, _ = QFileDialog.getSaveFileName(self, "Save file", "",
"Text documents (*.txt);All files (*.*)")
# if dialog is cancelled i.e no path is selected
if not path:
# return this method
# i.e no action performed
return
# else call save to path method
self._save_to_path(path)
# save to path method
def _save_to_path(self, path):
# get the text
text = self.editor.toPlainText()
# try catch block
try:
# opening file to write
with open(path, 'w') as f:
# write text in the file
f.write(text)
# if error occurs
except Exception as e:
# show error using critical
self.dialog_critical(str(e))
# else do this
else:
# change path
self.path = path
# update the title
self.update_title()
# action called by print
def file_print(self):
# creating a QPrintDialog
dlg = QPrintDialog()
# if executed
if dlg.exec_():
# print the text
self.editor.print_(dlg.printer())
# update title method
def update_title(self):
# setting window title with prefix as file name
# suffix aas PyQt5 Notepad
self.setWindowTitle("%s - PyQt5 Notepad" %(os.path.basename(self.path)
if self.path else "Untitled"))
# action called by edit toggle
def edit_toggle_wrap(self):
# chaning line wrap mode
self.editor.setLineWrapMode(1 if self.editor.lineWrapMode() == 0 else 0 )
# drivers code
if __name__ == '__main__':
# creating PyQt5 application
app = QApplication(sys.argv)
# setting application name
app.setApplicationName("PyQt5-Note")
# creating a main window object
window = MainWindow()
# loop
app.exec_()
Now if you run this python script by running the below command as shown below
python app.py
