Can not creating a flow graph


I reading this page
am try to run example1 “Dial Tone Output”, but I only listen to some
Why I can’t creating a flow graph? Maybe I type wrong command? What is
command should we type?

I use gnuradio-3.1.1 on the windows(cygwin).


Example 1. Dial Tone Output

#!/usr/bin/env python

from gnuradio import gr

from gnuradio import audio

def build_graph ():

sampling_freq = 48000

ampl = 0.1

fg = gr.flow_graph ()

src0 = gr.sig_source_f (sampling_freq, gr.GR_SIN_WAVE, 350, ampl)

src1 = gr.sig_source_f (sampling_freq, gr.GR_SIN_WAVE, 440, ampl)

dst = audio.sink (sampling_freq)

fg.connect ((src0, 0), (dst, 0))

fg.connect ((src1, 0), (dst, 1))

return fg

if name == ‘main’:

fg = build_graph ()

fg.start ()

raw_input ('Press Enter to quit: ')

fg.stop ()