add default argument. fix constructor

Author: valentin-pinkau

wkcuber/mag.py

@@ -18,7 +18,7 @@ def __init__(self, mag):
             elif re.match(r"^\d+-\d+-\d+$", mag) is not None:
                 self.mag = [int(m) for m in mag.split("-")]
 
-        if self.mag is None or len(mag) != 3:
+        if self.mag is None or len(self.mag) != 3:
             raise ValueError(
                 "magnification must be int or a vector3 of ints or a string shaped like e.g. 2-2-1"
             )

wkcuber/metadata.py

@@ -97,7 +97,7 @@ def detect_dtype(dataset_path, layer, mag: Mag = Mag(1)):
                 return str(np.dtype(voxel_type))
 
 
-def detect_cubeLength(dataset_path, layer, mag: Mag):
+def detect_cubeLength(dataset_path, layer, mag: Mag = Mag(1)):
     layer_path = path.join(dataset_path, layer, str(mag))
     if path.exists(layer_path):
         with wkw.Dataset.open(layer_path) as dataset: