Start with the following code:
from PyQt5.QtWidgets import *
Then type "QPu" on the second line and press Ctrl+Space (to open completion list). Scroll down to QPushButton in the list and highlight it. It will show a tooltip on the right of the completion list with the following signatures:
QPushButton(str, QWidget parent=None)
QPushButton(QIcon, str, QWidget parent=None)
These are the expected signatures. Now complete typing QPushButton and type ( to trigger argument help. It shows a tooltip with the sole signature being:
I would expect it to show the same signatures as in the completion list.
Also repros with PyQt4 on Python 2.7.