dxfgrabber-return lines start point

[elhetch]

Hi 
i wrote the below code to return the start point of the lines in drawing, but it return error:

import dxfgrabber
dwg = dxfgrabber.readfile("test.dxf")
print("DXF version:{} ".format(dwg.dxfversion))
all_lines = [entity for entity in dwg.entities if entity.line.start]
for line in all_lines:
    print(line.start)

Error:
Traceback (most recent call last):

    all_lines = [entity for entity in dwg.entities if entity.line.start]
AttributeError: 'Line' object has no attribute 'line'