Passing extra arguments through connect

Question

Is it possible to pass variables through slots so I can print out certain text? Trying to pass variable 'DiffP' which is defined in another function to slot.

'DiffP' changes based on which file is selected.

def addLineEdit(self):
    try:
        self.clearLayout()
        self.FileButton ={}
        self.Input = {}
        self.TotalInput = []
        for i in range(int(self.numberLine.text())):
            self.FileButton[i] = QtWidgets.QPushButton(self.centralwidget)
            self.FileButton[i].setText('Case {}'.format(i+1))
            self.FileButton[i].setFlat(True)
            self.FileButton[i].setMaximumSize(QtCore.QSize(50, 50))
            self.hboxlayout[0].addWidget(self.FileButton[i])
            self.FileButton[i].clicked.connect(lambda i=i: self.openfile(i))
            self.buttonGroup.addButton(self.FileButton[i],i)
            self.buttonGroup.buttonClicked['int'].connect(self.input)

def searchfile(self,dir):
        with open(dir) as f:
            content = f.readlines()
            MainList = content[44].split()
            RPM = round(float(MainList[0]), 2)
            Ps = round(float(MainList[1]), 2)
            Ts = round(float(MainList[2]), 2)
            Pd = round(float(MainList[3]), 2)
            Ratio = round(Pd / Ps, 2)
            DiffP = round(Pd - Ps, 2)
@pyqtSlot(int)
def input(self,button_or_id,DiffP):
    if isinstance(button_or_id, int):
        if button_or_id == 0:
            self.TotalInput[0].setText(str(DiffP))
        elif button_or_id == 1:
            self.TotalInput[54].setText('1')

def openfile(self,i):
    filename = QtWidgets.QFileDialog.getOpenFileName(self, 'Choose file')
    dir = filename[0]
    directory = os.path.split(dir)[0]
    return self.searchfile(dir)

Answer 1

The problem can be solved in 2 ways:

Using lambda functions:

In general:

    obj.signal.connect(lambda param1, param2, ..., arg1=val1, arg2= value2, ... : fun(param1, param2,... , arg1, arg2, ....))

def fun(param1, param2,... , arg1, arg2, ....):
    [...]

where:

• param1, param2, ... : are the parameters sent by the signal
• arg1, arg2, ...: are the extra parameters that you want to spend

In your case:

    self.buttonGroup.buttonClicked['int'].connect(lambda i: self.input(i, "text"))

@pyqtSlot(int)
def input(self, button_or_id, DiffP):
    if isinstance(button_or_id, int):
        if button_or_id == 0:
            self.TotalInput[0].setText(DiffP)
        elif button_or_id == 1:
            self.TotalInput[54].setText('1')

---

Using functools.partial:

In general:

    obj.signal.connect(partial(fun, args1, arg2, ... ))

def fun(arg1, arg2, ..., param1, param2, ...):
    [...]

where:

• param1, param2, ... : are the parameters sent by the signal
• arg1, arg2, ...: are the extra parameters that you want to send

In your case:

from functools import partial

    [...]
    self.buttonGroup.buttonClicked['int'].connect(partial(self.input, "text"))


@pyqtSlot(int)
def input(self, DiffP, button_or_id):
    if isinstance(button_or_id, int):
        if button_or_id == 0:
            self.TotalInput[0].setText(DiffP)
        elif button_or_id == 1:
            self.TotalInput[54].setText('1')