What’s PyQt5?

PyQt is a library that lets you use the Qt GUI framework from Python. Qt itself is written in C++. By using it from Python, you can build applications much more quickly while not sacrificing much of the speed of C++.

PyQt5 refers to the most recent version 5 of Qt. You may still find the occasional mention of (Py)Qt4 on the web, but it is old and no longer supported.

Creating a GUI

import pyqt5 modules

from PyQt5.QtWidgets import QApplication, QLabel

The QApplication class manages the GUI application’s control flow and main settings.
A QLabel object acts as a placeholder to display non-editable text or image, or a movie of animated GIF.

create a QApplication

This is a requirement of Qt: Every GUI app must have exactly one instance of QApplication. Many parts of Qt don’t work until you have executed the above line. You will therefore need it in virtually every (Py)Qt app you write.

app = QApplication([])

The brackets [] in the above line represent the command line arguments passed to the application. Because our app doesn’t use any parameters, we leave the brackets empty.

create a QLabel

label = QLabel('Hello World!')
label.show()

Workout Problem

Create an interface which can display the output of shell command(s)

Create the layout design

Start the Qt Designer Tool

designer &

Create the layout

Create two PlainTextFields for taking input and showing output
Create a push button to run the command

Use the pyuic module to convert ui to py

python3 -m PyQt5.uic.pyuic -x xml.ui -o output.py

Run the file

python3 output.py

Create an API for getting the user inputted command and showing its output

Connect the push button to call the api on being clicked

self.pushButton.clicked.connect(self.run_command())

Define the run_command() api

def run_command(self):
    txt = str(self.plainTextEdit_input.toPlainText())
    process = subprocess.Popen(
       txt, shell=True, stdout=subprocess.PIPE,
       stderr=subprocess.STDOUT)
    out,err = process.communicate()
    self.plainTextEdit_output.insertPlainText(str(out,"utf-8"))

yedhink / pyqt5-examples