results.txt

C++ version:

pixel at 0 0 is r = 255 g = 0 b = 0
pixel at 1 0 is r = 0 g = 255 b = 0
pixel at 0 1 is r = 0 g = 0 b = 255
pixel at 1 1 is r = 0 g = 0 b = 128

Python version:

pixel at 0,0 is r = 0, g = 0, b = 0
pixel at 1,0 is r = 0, g = 0, b = 0
pixel at 0,1 is r = 0, g = 0, b = 255
pixel at 1,1 is r = 0, g = 0, b = 0

tst.cpp

#include <QImage>
#include <QColor>
#include <QDebug>

int main(int, char *[]) {
    QImage image(2, 2, QImage::Format_RGB32);
    image.setPixel(0, 0, QColor(Qt::red).rgb());
    image.setPixel(1, 0, QColor(Qt::green).rgb());
    image.setPixel(0, 1, QColor(Qt::blue).rgb());
    image.setPixel(1, 1, QColor(Qt::darkBlue).rgb());

    for (int y = 0; y < image.height(); ++y) {
        const auto scanLine = (QRgb *)image.scanLine(y);
        for (int x = 0; x < image.width(); ++x) {
            const auto pixel = scanLine[x];
            qDebug() << "pixel at" << x << y << "is"
                << "r =" << qRed(pixel)
                << "g =" << qGreen(pixel)
                << "b =" << qBlue(pixel);
        }
    }

    return 0;
}

tst.py

from PySide2.QtCore import Qt
from PySide2.QtGui import QImage, qRed, qGreen, qBlue, QColor

image = QImage(2, 2, QImage.Format_RGB32)
image.setPixel(0, 0, QColor(Qt.red).rgb())
image.setPixel(1, 0, QColor(Qt.green).rgb())
image.setPixel(0, 1, QColor(Qt.blue).rgb())
image.setPixel(1, 1, QColor(Qt.darkBlue).rgb())

for y in range(image.height()):
    scanLine = image.scanLine(y)
    for x in range(image.width()):
        pixel = scanLine[x]
        print('pixel at {},{} is r = {}, g = {}, b = {}'.format(
            x, y, qRed(pixel), qGreen(pixel), qBlue(pixel)))