Various problems with arches when importing DXF created with AutoCad

[18buste]

Hi,
First of all, I apologize because I certainly committed a sin of presumption in my approach to writing the Python language which turned out to be more complex than expected.
I looked for the solution to my problem on the forum but nothing seems to work so I decided to ask!

I wrote a fairly complex program to display DXF files on the screen but when I import those created with inventor/autocad I have two main problems in managing the arcs.

The first problem is that when I import a figure made up of a single polyline into my program, no arcs are detected (only bulge 0, but by analyzing the file with a text editor the bulge has a value other than zero) and therefore the arc is replaced by a straight line.

The second problem is that if I "explode" the polyline (to overcome the previous problem) into segments (therefore into a group of separate lines and arcs) the arcs, sometimes, are seen developed on the opposite side to which they should be, or rather , if they should be concave they are seen as convex and vice versa.

Below I attach some explanatory photos.
The images on a "grey/light blue" background are the files seen on DWG trueview, while the images on a white background are the results of my program.

I tried every way to correct these problems for three days straight, but I don't know what to do anymore!

Thank you so much to everyone who can help me!

p.s. I deleted the script because in the meantime I improved it but the problems persist