QPushButton clicked signal not received by main window

How to handle widget events using PyQt signal and slot mechanism signal slot At the core of the signal-slot mechanism are the queues that are used to pass messages between processes Python provides a default implementation signal and slot When one QObject instance is the receiver of a signal, its thread affinity is checked, and by default the signal is delivered directly as a

signal and slot qt The signals and slots mechanism is type safe The signature of a signal must match the signature of the receiving slot