PyQT - AttributeError: 'Ui_Form' object has no attribute 'output_text'

Ahojte, nejako tomu nechapem, co je atribut resp. ako pristupovat k Widgetom. Mam dva python moduly. Jeden sa vola GPS.py a druhy comm.py. Potrebujem, aby funkcia uart_rx (comm.py) pridala text do output_text (gps.py). Skonci to vsak chybou AttributeError: 'Ui_Form' object has no attribute 'output_text'. Prosim, poradite mi ?

gps.py

from PyQt4 import QtCore, QtGui
import comm

       

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName(_fromUtf8("Form"))
        Form.resize(796, 683)
        self.output_text = QtGui.QTextEdit(Form)
        self.output_text.setGeometry(QtCore.QRect(10, 13, 761, 461))
        self.output_text.setObjectName(_fromUtf8("output_text"))
        self.widget = QtGui.QWidget(Form)
        self.widget.setGeometry(QtCore.QRect(10, 500, 761, 33))
        self.widget.setObjectName(_fromUtf8("widget"))
        self.horizontalLayout = QtGui.QHBoxLayout(self.widget)
        self.horizontalLayout.setObjectName(_fromUtf8("horizontalLayout"))
        self.send = QtGui.QPushButton(self.widget)
        self.send.setObjectName(_fromUtf8("send"))
        self.horizontalLayout.addWidget(self.send)
        self.tr_send = QtGui.QLineEdit(self.widget)
        self.tr_send.setObjectName(_fromUtf8("tr_send"))
        self.horizontalLayout.addWidget(self.tr_send)
        self.send.raise_()
        self.tr_send.raise_()
        self.output_text.raise_()
        self.output_text.raise_()
        
        self.send.clicked.connect(comm.uart_rx)
      

        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(_translate("Form", "Form", None))
        self.send.setText(_translate("Form", "Send", None))


if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    Form = QtGui.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())

comm.py


import serial
import gps


def uart_tx():
        
    if (ser.isOpen()):
        print "Open"
            
def uart_rx():
    try:
        ser = serial.Serial('/dev/ttyACM0')
        ser.write("l\n")
        
    except:
        print "Error"
    
     
    while ser.isOpen():
        tmp = ser.read(100)
        print tmp
        ui = gps.Ui_Form()
        ui.output_text.append(tmp)