bm.loops.layers.uv

>>> bm.loops.layers.uv
<BMLayerCollection object at 0x7efeed558e90>

>>> bm.loops.layers.uv.active
<BMLayerItem object at 0x7efeed453a20>

>>> uv_lay
<BMLayerItem object at 0x7efeed453b40>

>>> loop[uv_lay].uv
Vector((0.20000000298023224, 35.79999923706055))

>>> loop[uv_lay]
<BMLoopUV object at 0x7efeeda874f0>

>>> loop[uv_lay].
                 pin_uv
                 select
                 select_edge
                 uv
>>> loop[uv_lay].