num_samples should be a positive integer value, but got num_samples=0

[LMeteorYu0330]

got error when running python example/gsplat/simple_trainer_difix3d.py
in line 566, in train of simple_trainer_difix3d.py

[Catchip]

In short, Difix3D requires the image filename to contain either "train" or "eval".

Corresponding code section