PyQtGraph

0.14.0 · active · verified Sun Apr 12

PyQtGraph is an open-source Python library for scientific graphics and GUI development, built on top of Qt and NumPy. It provides fast, interactive plotting for large datasets, signal/image processing, and sophisticated GUI elements, making it ideal for scientific and engineering applications. The current version is 0.14.0, and it maintains a relatively active release cadence with several minor and patch releases per year.

Warnings

breaking The classes `MetaArray`, `MultiPlotItem`, and `MultiPlotWidget` have been removed.
Fix: Review your code for usage of these deprecated classes. For multi-plotting, consider using `GraphicsLayoutWidget` with multiple `PlotItem` instances or alternative approaches.
breaking Support for Python 3.8 and NumPy 1.20 has been dropped.
Fix: Upgrade your Python environment to 3.9 or higher and NumPy to version 1.21 or higher to ensure compatibility.
breaking Minimum supported Qt versions have been increased to Qt5 5.15 and Qt6 6.2+.
Fix: Ensure your installed Qt binding (PyQt5, PyQt6, PySide2, or PySide6) meets these minimum version requirements. Upgrade your Qt binding if necessary.
deprecated The `GraphicsObject::parentChanged` method has been deprecated.
Fix: Avoid using `GraphicsObject::parentChanged`. Look for alternative signals or methods if you were relying on this for parent change detection.
gotcha Forgetting to start the Qt event loop or calling `QApplication.exec_()` (or `exec()`) can lead to the GUI window appearing briefly and then closing, or not appearing at all.
Fix: Always include `app.exec_()` (or `app.exec()` on some platforms/Qt versions) at the end of your script after setting up your GUI, typically guarded by `if __name__ == '__main__':`.

Install

pip install pyqtgraph Base installation (requires separate Qt binding)
pip install pyqtgraph[PyQt6] Install with PyQt6 binding
pip install pyqtgraph[PySide6] Install with PySide6 binding
pip install pyqtgraph[PyQt5] Install with PyQt5 binding
pip install pyqtgraph[PySide2] Install with PySide2 binding

Imports

pyqtgraph
```
import pyqtgraph as pg
```

QtWidgets, QtCore

from pyqtgraph.Qt import QtWidgets, QtCore

mkQApp
```
app = pg.mkQApp('Your App Name')
```
While `QApplication` works, `pg.mkQApp` is the recommended way to create or retrieve the QApplication instance, ensuring proper initialization and avoiding issues if an instance already exists.

Quickstart

This quickstart demonstrates how to create a basic line plot using PyQtGraph. It sets up a QApplication, creates a `GraphicsLayoutWidget` as the main window, adds a plot item, and plots a simple list of data. Crucially, it uses `pg.mkQApp` for application initialization and `app.exec_()` to start the Qt event loop, allowing the GUI to run.

import pyqtgraph as pg
from pyqtgraph.Qt import QtWidgets

# Always start by creating a QApplication
app = pg.mkQApp("PyQtGraph Quickstart")

# Create a GraphicsLayoutWidget (a window to hold plots)
win = pg.GraphicsLayoutWidget(show=True, title="Basic Plot")
win.resize(800, 500)
win.setWindowTitle('PyQtGraph Quickstart Example')

# Enable antialiasing for prettier plots
pg.setConfigOptions(antialias=True)

# Add a plot item to the window
p = win.addPlot(title="Simple Line Plot")

# Generate some data
data = [1, 5, 2, 4, 3, 8, 9, 1, 2, 3, 5]

# Plot the data
p.plot(data)

# Start the Qt event loop if running as a script
if __name__ == '__main__':
    QtWidgets.QApplication.instance().exec_()

view raw JSON →