We supplied a min and max value to constrain the value. The first value is the actual value entered by the user, the second value is whether or not the user pressed the “ok” button. The first thing to note is that we get two values which we'll have to unpack after calling QInputDialog.getDouble. Yearly_tText('Yearly Income: $%'.format(rate)) We need to define the callback that will be called when this button is pressed: def open_calculator(): Let's add a “calculator” button: button = QPushButton() Creating a Button and Opening a QInputDialog The yearly income label is in the first column with the tax rate label is in the second column. Both of the labels are in the same row, 0. We’re using the QLabel widget for this and formatting the text in a particular way, before adding each widget to the grid layout. Tax_tText('Highest Marginal Tax Rate: 0%') We need something to display on the screen, so let’s start with something basic: two labels that show the freelancer’s yearly income and the top marginal tax rate they should be prepared for come tax season: yearly_income = QLabel() The app.exec_ kickstarts the Qt event loop.
![python pyqt5 python pyqt5](https://i.stack.imgur.com/dm12m.png)
![python pyqt5 python pyqt5](https://codeloop.org/wp-content/uploads/2020/06/pyqt5-calculator-e1594356105266.jpg)
This will set the screen widget as the one to display, the title and size of the window, and show it.
#PYTHON PYQT5 CODE#
This is a good default, but for more complex desktop apps, you will want to evaluate the other layouts that are possible with Qt.Īfter all the widgets are created we will have this code at the very bottom of the file: tCentralWidget(screen) We’re importing all the Qt widgets we need, and setting up the application and window. QWidget, QPushButton, QTableWidget, QTableWidgetItem, QInputDialog Let's start with some of the structure we used in the Hello World app: # freelancer.pyįrom PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QGridLayout, \
#PYTHON PYQT5 FULL#
You can view the full source code for this app here. The window is going to show a table of weekly earnings and allow the freelancer to calculate which marginal tax bracket they fall under by using a dialog box. Now that we've practiced with a simple Hello World app, let's build a desktop app for freelance developers. Then we'll add it to the first row and column: layout.addWidget(label, 0, 0)Īfter that, we’re going to set the window widget to the layout widget, show the window, and start the Qt event loop which'll start the app: tCentralWidget(widget) Now, let’s create the “Hello world!” label: label = QLabel() With Qt, it’s built in and much easier to do. If you were using Electron or making a web app, you would use something like Bootstrap CSS framework or CSS Flexbox to make a grid layout. We’re using a grid layout where each widget added to the layout can be placed precisely into a particular row and column, and can span multiple rows or columns. There are other layout types that can be used, such as VBoxLayout to lay out widgets in a vertical direction, or you can use an HBoxLayout for a horizontal layout. To make a layout in Qt, you have to use a generic QWidget object because the window will display one widget at a time. Next, let's set up the application, the window, and layout for the window: app = QApplication() They are also known as components in other frameworks. Widgets are the objects that are drawn on the screen as part of the graphical user interface in Qt. We’re going to start by importing the PyQt5 widgets we'll need: # hello.pyįrom PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QGridLayout, QWidget Let’s start with a simple example that displays “Hello World”. The former documentation covers the major aspects of the PyQt interfact, while the latter is for the C++-based API of Qt. You can reference the documentation for PyQt here and if some of the documentation is lacking, you can refer to the official Qt library documentation here.
![python pyqt5 python pyqt5](https://files.realpython.com/media/qt-designer.bd1e2f5392c8.gif)
#PYTHON PYQT5 INSTALL#
You can install PyQt by installing Python and using pip with this command: pip install PyQt5 You'll need a little bit of Python coding to follow this tutorial. First, we’ll build a Hello World app before building a more useful desktop app for freelancer developers to calculate their taxes and hourly rates. It might be less popular, but I’m going to show you how effective PyQt5 can be for producing a desktop app. Qt is a graphical user interface toolkit for building desktop applications. PyQt5 is the interface that lets you use the C++-based Qt library from within Python. One popular option for developing cross-platform desktop apps is Electron and JavaScript. There are also times when an app has to be very memory efficient and will need to have low latency (graphic intensive apps, for example).
#PYTHON PYQT5 WINDOWS#
For instance, apps like Adobe After Effects or Word are still mainly used on the desktop so they can use dialog windows and keyboard shortcuts to improve the user's workflow. Web apps are very popular, but there are still times when only a desktop app can deliver a great user experience.