test.py --task test updates

test.py

@@ -165,7 +165,7 @@ def test(data,
 
     # Compute statistics
     stats = [np.concatenate(x, 0) for x in zip(*stats)]  # to numpy
-    if len(stats):
+    if len(stats) and stats[0].any():
         p, r, ap, f1, ap_class = ap_per_class(*stats)
         p, r, ap50, ap = p[:, 0], r[:, 0], ap[:, 0], ap.mean(1)  # [P, R, AP@0.5, AP@0.5:0.95]
         mp, mr, map50, map = p.mean(), r.mean(), ap50.mean(), ap.mean()

utils/datasets.py

@@ -416,7 +416,10 @@ class LoadImagesAndLabels(Dataset):  # for training/testing
 
             pbar.desc = 'Scanning labels %s (%g found, %g missing, %g empty, %g duplicate, for %g images)' % (
                 cache_path, nf, nm, ne, nd, n)
-        assert nf > 0, 'No labels found in %s. See %s' % (os.path.dirname(file) + os.sep, help_url)
+        if nf == 0:
+            s = 'WARNING: No labels found in %s. See %s' % (os.path.dirname(file) + os.sep, help_url)
+            print(s)
+            assert not augment, '%s. Can not train without labels.' % s
 
         # Cache images into memory for faster training (WARNING: large datasets may exceed system RAM)
         self.imgs = [None] * n