How to show timer in a Quiz Application using pyqt5 python

Question

I am new to pyqt5. I have to make a quiz application, in which total time will be equal to total number of questions. I have get the total time, but I don't know that how to show that time while displaying the quiz. I have tried some code but it is freezing the user interface.

I have this timer code which is freezing the GUI

def Time(self):
    self.seconds = self.total_time * 60
    for self.remaining in range(self.seconds, 0, -1):
        self.minutes = 0
        self.seconds = self.remaining
        if self.remaining > 60:
            self.minutes = int(self.seconds / 60)
            self.seconds = int(self.seconds % 60)
        else:
            self.seconds = self.remaining
        self._time = "{:2d} minutes {:2d} seconds remaining.".format(self.minutes, self.seconds)
        self.disp_time_label.setText(self._time)
        time.sleep(1)
    self.disp_time_label.setText("Time Ends")

Fetching total time from here

def fetchTotalTime_and_TotalMarks(self):
    query = "SELECT q_id FROM EntranceExam_Quiz_Application.dbo.tbl_questions"
    conn = createConnection()
    connection = conn.cursor()
    connection.execute(query)
    rows = connection.fetchall()
    conn.commit()
    self.q_no_list = []
    self.q_row_len = []

    for i in rows:
        self.q_row_len.append(len(i))
        self.q_no_list.append(i.q_id)
    self.total_time = len(self.q_row_len)
    self.total_marks = len(self.q_row_len)

Calling this both methods in _retranlateUi

def retranslateUi(self, Quiz):
  self.self.fetchTotalTime_and_TotalMarks()
  self.Time()

I want to display time according to total number of questions, continuously updating the label text which is showing time.