This property is deprecated and will be removed in version 1.2.0.
dt.stype for all columns.
This property is well-defined only for frames where all columns have the same stype.
For frames where all columns have the same stype, this common
stype is returned. If a frame has 0 columns,
None will be
This exception will be raised if the columns in the frame have different stypes.
.stypes– tuple of stypes for all columns.