Qt: Understanding QScrollArea::widgetResizable property - qt

Question

I am experimenting with Qt 5 QScrollArea (in Python and PyQt, but I believe the question applies just as well in C++ Qt).
The Qt documentation for QScrollArea::widgetResizable says that "If this property is set to false (the default), the scroll area honors the size of its widget." By "its widget", I assume it means the widget being viewed in the scroll area.
However, in the program below I show an image label inside the scroll area, but the scroll area does not seem to "honor the size of its widget", because the image is partly hidden from the start.
The documentation also says "Regardless of this property, you can programmatically resize the widget using widget()->resize(), and the scroll area will automatically adjust itself to the new size." However, I do invoke resize for the viewed widget, but nothing happens.
The documentation also says "If this property is set to true, the scroll area will automatically resize the widget in order to avoid scroll bars where they can be avoided, or to take advantage of extra space." However, I don't see any resizing, even though if the widget were resized then it would be possible to avoid the scroll bars.
This is what I see whether I set the property to True or False, and whether I invoke widget().resize() or not:
Clearly I must be missing something quite fundamental here; what is it?
Edit: the main purpose of the question is understanding how widgetResizable works and what it does. Fitting the image into the window is a secondary goal.
from PyQt5.QtCore import QSize
from PyQt5.QtGui import QImage, QPalette, QPixmap
from PyQt5.QtWidgets import QMainWindow, QApplication, QLabel, QScrollArea
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
image = QImage("happyguy.png")
imageLabel = QLabel()
imageLabel.setPixmap(QPixmap.fromImage(image))
scrollArea = QScrollArea()
scrollArea.setBackgroundRole(QPalette.Dark)
scrollArea.setWidget(imageLabel)
scrollArea.setWidgetResizable(True)
scrollArea.widget().resize(QSize(10, 10))
self.setCentralWidget(scrollArea)
app = QApplication([])
w = MainWindow()
w.show()
app.exec_()
And here's the happyguy.pgn file:

Answer 1

scrollArea.setWidgetResizable(True) give the resize control of imageLabel to scrollArea. So the next line scrollArea.widget().resize(QSize(10, 10)) will be overrode by system.
A solution worked on windows (resize main window to fit image size).
from PyQt5.QtGui import QImage, QPalette, QPixmap
from PyQt5.QtWidgets import QMainWindow, QApplication, QLabel, QScrollArea, QFrame
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
image = QImage("happyguy.png")
imageLabel = QLabel()
imageLabel.setPixmap(QPixmap.fromImage(image))
scrollArea = QScrollArea()
scrollArea.setFrameShape(QFrame.NoFrame)
scrollArea.setBackgroundRole(QPalette.Dark)
scrollArea.setWidget(imageLabel)
self.setCentralWidget(scrollArea)
self.resize(image.size())
app = QApplication([])
w = MainWindow()
w.show()
app.exec_()
Or use QScrollArea.setMinimumSize
from PyQt5.QtGui import QImage, QPalette, QPixmap
from PyQt5.QtWidgets import QMainWindow, QApplication, QLabel, QScrollArea, QFrame
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
image = QImage("happyguy.png")
imageLabel = QLabel()
imageLabel.setPixmap(QPixmap.fromImage(image))
scrollArea = QScrollArea()
scrollArea.setFrameShape(QFrame.NoFrame)
scrollArea.setBackgroundRole(QPalette.Dark)
scrollArea.setWidget(imageLabel)
scrollArea.setMinimumSize(image.size())
self.setCentralWidget(scrollArea)
app = QApplication([])
w = MainWindow()
w.show()
app.exec_()

Answer 2

Resizable IS NOT Scrollable ...