[Discuss-gnuradio] error after compiling grc

#!/usr/bin/env python
##################################################
# Gnuradio Python Flow Graph
# Title: Top Block
# Generated: Wed Jul 27 11:54:58 2011
##################################################

from gnuradio import gr
from gnuradio.eng_option import eng_option
from gnuradio.wxgui import scopesink2
from grc_gnuradio import wxgui as grc_wxgui
from optparse import OptionParser
import comedi
import wx

class top_block(grc_wxgui.top_block_gui):

def __init__(self):
grc_wxgui.top_block_gui.__init__(self, title="Top Block")

##################################################
# Variables
##################################################
self.samp_rate = samp_rate = 32000

##################################################
# Blocks
##################################################
self.comedi_source_s_0 = comedi.source_s()
self.wxgui_scopesink2_0 = scopesink2.scope_sink_f(
self.GetWin(),
title="Scope Plot",
sample_rate=samp_rate,
v_scale=0,
t_scale=0,
ac_couple=False,
xy_mode=False,
num_inputs=1,
)
self.Add(self.wxgui_scopesink2_0.win)

##################################################
# Connections
##################################################
self.connect((self.comedi_source_s_0, 0), (self.wxgui_scopesink2_0, 0))

def set_samp_rate(self, samp_rate):
self.samp_rate = samp_rate
self.wxgui_scopesink2_0.set_sample_rate(self.samp_rate)

if __name__ == '__main__':
parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
(options, args) = parser.parse_args()
tb = top_block()
tb.Run(True)

hi ,
i am working on GNURadio . after compiling i am getting the error . will some tell me what this error is related to.
please check attachment for top_block.py file

Traceback (most recent call last):   File "/home/jagdish/top_block.py", line 54, in <module>     tb = top_block()   File "/home/jagdish/top_block.py", line 29, in __init__     self.comedi_source_s_0 = comedi.source_s() AttributeError: 'module' object has no attribute 'source_s'