Improve check for bbox

oscargus · oscargus · commit c8e34e3f621f · 2023-12-14T10:40:26.000+01:00
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -1101,7 +1101,7 @@ def __init__(self, bbox, transform, **kwargs):
         bbox : `Bbox`
         transform : `Transform`
         """
-        if not bbox.is_bbox:
+        if not hasattr(bbox, 'is_bbox') or not bbox.is_bbox:
             raise ValueError("'bbox' is not a bbox")
         _api.check_isinstance(Transform, transform=transform)
         if transform.input_dims != 2 or transform.output_dims != 2:
@@ -1190,7 +1190,7 @@ def __init__(self, bbox, x0=None, y0=None, x1=None, y1=None, **kwargs):
             The locked value for y1, or None to leave unlocked.
 
         """
-        if not bbox.is_bbox:
+        if not hasattr(bbox, 'is_bbox') or not bbox.is_bbox:
             raise ValueError("'bbox' is not a bbox")
 
         super().__init__(**kwargs)
@@ -2547,7 +2547,8 @@ def __init__(self, boxin, boxout, **kwargs):
         Create a new `BboxTransform` that linearly transforms
         points from *boxin* to *boxout*.
         """
-        if not boxin.is_bbox or not boxout.is_bbox:
+        if (not hasattr(boxin, 'is_bbox') or not hasattr(boxout, 'is_bbox') or
+                not boxin.is_bbox or not boxout.is_bbox):
             raise ValueError("'boxin' and 'boxout' must be bbox")
 
         super().__init__(**kwargs)
@@ -2591,7 +2592,7 @@ def __init__(self, boxout, **kwargs):
         Create a new `BboxTransformTo` that linearly transforms
         points from the unit bounding box to *boxout*.
         """
-        if not boxout.is_bbox:
+        if not hasattr(boxout, 'is_bbox') or not boxout.is_bbox:
             raise ValueError("'boxout' must be bbox")
 
         super().__init__(**kwargs)
@@ -2645,7 +2646,7 @@ class BboxTransformFrom(Affine2DBase):
     is_separable = True
 
     def __init__(self, boxin, **kwargs):
-        if not boxin.is_bbox:
+        if not hasattr(boxin, 'is_bbox') or not boxin.is_bbox:
             raise ValueError("'boxin' must be bbox")
 
         super().__init__(**kwargs)
