I'm building a GUI in python 2.7 with pyqt4. I wanted to link a button to a script and someone provided me the following code:
from PyQt4 import QtGui
import sys
# --- functions ---
def my_function(event=None):
print 'Button clicked: event:', event
print linetext.text()
# run your code
# --- main ---
app = QtGui.QApplication(sys.argv)
window = QtGui.QWidget()
# add "layout manager"
vbox = QtGui.QVBoxLayout()
window.setLayout(vbox)
# add place for text
linetext = QtGui.QLineEdit(window)
vbox.addWidget(linetext)
# add button
button = QtGui.QPushButton("Run", window)
vbox.addWidget(button)
# add function to button
button.clicked.connect(my_function)
window.show()
sys.exit(app.exec_())
I don't understand why you would pass the event=None as an argument for my_function. When I run the script without the event parts it works fine.
It's not needed.
In Qt, events and signals/slots are two separate systems. Generally speaking, events ultimately come from outside of the application (e.g. keyboard presses, mouse moves, etc), whilst signals come from within the application.
A click is a combination of events (mouse-press + mouse-release), which are initially handled internally by Qt. The event handlers then emit the clicked signal whenever appropriate.
The clicked signal actually sends its checked-state (i.e. True or False), rather than an event object. But that is not really relevant in your script (that is, you don't need to provide an argument for it).