#!/usr/bin/python
     
import MySQLdb 
import sys
from PyQt4 import QtCore,QtGui
db = MySQLdb.connect(host="localhost", user="root", passwd="xxx", db="dev", charset='utf8')     
class GridLayout(QtGui.QWidget):
  def __init__(self, parent=None):
             QtGui.QWidget.__init__(self, parent)
             
             def slotSaveNumber(num=0):
               sql="INSERT INTO numbers SET number =('"+str(num)+"')"
               cursor = db.cursor()
               cursor.execute(sql)  
             self.setWindowTitle('test')
     
             names = ['1', '2', '3']
     
             grid = QtGui.QGridLayout()
     
             j = 0
             pos = [(0,0),(0,1),(0,2)]
     
             for i in names:
                 button = QtGui.QPushButton(i)
                 grid.addWidget(button, pos[j][0], pos[j][1])
                 #self.connect(button,QtCore.SIGNAL("clicked()"),app,slotSaveNumber(2))  
                   self.connect(button,QtCore.SIGNAL("clicked()"),app,slotSaveNumber)  
                 j = j + 1
                 
  
             self.setLayout(grid)
app = QtGui.QApplication(sys.argv)
qb = GridLayout()
qb.show()
sys.exit(app.exec_())

self.connect(button, QtCore.SIGNAL("clicked()"), lambda: slotSaveNumber(2))