How to append data to shapefile?

Question

I have a shapefile. and some data there. It's the way I created it:

w = shapefile.Writer('shapefiles/test/line_2')
w.field('Latitude','C')
w.poly(arr)
w.record('linestring3')
w.close()

Now, I want to append data to this shapefile. How it can be done?

Thanks