DXF Rotate

[softy2k]

Hello

I am trying to rotate (mirror) a DXF file (gerber). Just rotate the whole DXF by a certain number of degrees, nothing special.
I state from the beginning that this is my first contact with Python and with DXF files.

So, I installed Python : pip install ezdxf, then pip install ezdxf[draw] (I don't know if the second step was necessary).

Then, I tried various options, but without success.
E.g:

import ezdxf
doc = ezdxf.readfile('c:/input.dxf')
msp = doc.modelspace()
angle = 0.7853981634 # 45 degrees in radians
msp.rotate(angle)
doc.saveas('c:/output.dxf')

, but I get an error message: AttributeError: 'Modelspace' object has no attribute 'rotation'

I also attach the file that I want to rotate.
Basically, I'm looking for a simple method (regardless of which) to rotate a DXF file.
Thanks in advance for any help.

input.zip

[mozman]

You cannot rotate the modelspace, you have to rotate the entities of the modelspace:

for e in msp:
    e.rotate_z(angle)

This rotates all entities of the modelspace around the z-axis in the origin (0, 0), this may raise a NotImplementedError for unsupported entities.

BTW: Rotation is nothing special for a CAD application, but ezdxf is a file format interface and not a CAD application!

[softy2k]

Thank you very much, it works.
But I can't turn it so that what is up is down and vice versa. I also tried the x, y and z axis with various angles (-180 to 180).
I must be doing something wrong, but I still don't know what...

[mozman]

Mirroring is scaling by -1!

[softy2k]

I've tried various options, but still haven't succeeded.

for e in msp:
    e.scale(-1, 1, 1)

If I try:

for e in msp:
    e.scale(-1)

TypeError: DXFGraphic.scale() missing 2 required positional arguments: 'sy' and 'sz'

[mozman]

import ezdxf

doc = ezdxf.new()
msp = doc.modelspace()
pline = msp.add_lwpolyline(([(1, 1), (3, 2), (1, 3)]))
doc.saveas("test.dxf")

pline.scale(-1, 1, 1)
doc.saveas("test_sx.dxf")

test.dxf:

test_sx.dxf:

[softy2k]

Thanks for the reply.

I found the problem. And the code I wrote was OK, but the problem was the application with which I opened the DXFs.

More precisely with

DWG TrueView 2023
DWG FastView
DoubleCAD XT 5
and some online web viewer

DXFs were displayed correctly rotated.

With the applications:

FreeCAD 0.20
DXF Viewer
LibreCAD

the same rotated DXFs were not displayed correctly.
For this reason I was testing and could not find the solution.

I don't know why this happens, I used the applications with the default settings, on Windows 10 Pro (64 bits)