[Python] Passing data between classes with Signals in PyQt

I have got two different classes that I need to connect using a signal that sends text in a variable from one class, to another.

The first class is a Matplotlib figure. I added a QPushButton in the navigation toolbar to access a QDialog (which is the other class) with a QLineEdit. I need to send the text written in the QLineEdit to the Matplotlib figure´s class, using a variable, so I can create a note in the figure.

This is the code so far:

class Dialog(QDialog):

list_of_notes = [] #I create a list to add text, each time I open the QDialog

def __init__(self):
#A lot of stuff in here

def printVariable(self, text):
Dialog.lisf_of_notes.append(text)
MatplotlibFigure().addNote()

self.close()

class MatplotlibFigure(QMainWindow):
def __init__(self):
#A lot of stuff in here

self.axes = self.figure_canvas.figure.add_subplot(111)

def addNote(self):
for i,s in enumerate(Dialog.list_of_notes):
note = self.axes.annotate(i, xy=(0.2, 0.2)) #This is the note I want to create
note.draggable()
self.figure_canvas.draw_idle()


So, when I press the button "Accept" in the QDialog I can see that the text is added to the list, each time that I open the dialog. But, when I want to create the note from the last object that I added to the list, in the for loop nothing happens.

What is the problem? Hope you can help me.

----------------Edit-----------------------------


I´ve made some modifications. I created a signal mysignal to emit the variable text, which have the text that I wrote in the QDialog.

This is the modificated code:

class Dialog(QDialog):
def __init__(self, my_figure):

mysignal = pyqtSignal(str)

self.my_figure = MatplotlibFigure()
QDialog.__init__(self)

self.connect(self.btn_accept, SIGNAL("clicked()"), self.send_text)
self.mysignal.connect(self.printVariable)

def send_text(self): #I get the text from the QLineEdit and send it using
text = self.lineEdit.text() #the created signal
self.mysignal.emit(text)

def printVariable(self, text):
self,my_figure.addNote(text)
self.close()

class MatplotlibFigure(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.notes_list =[]

def openDialog(self, text): #I open the QDialog clicking a button
textMat = Dialog(text)
textMat.exec_()

def addNote(self, text):
self.notes_list.append(text)

notes = self.axes.annotate(text, xy=(0.2, 0.2), bbox = dict(facecolor="red"))
notes.draggable()
self.figure_canvas.draw_idle()


So, I open the QDialog and I can write the text. It is added to the list correctly, but the note is still not drawn in the figure.

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