def build_hover_tooltips(hover_spec=None, chart_cols=None):
 if isinstance(hover_spec, bool):
  tooltips = [(col, ('@' + col)) for col in chart_cols]
 elif isinstance(hover_spec[0], tuple):
  tooltips = hover_spec
 else:
  tooltips = [(col, ('@' + col)) for col in hover_spec]
 return tooltips

def build_hover_tooltips ( hover_spec = None , chart_cols = None ) : if isinstance ( hover_spec , bool ) : tooltips = [ ( col , ( '@' + col ) ) for col in chart_cols ] elif isinstance ( hover_spec [ 0 ] , tuple ) : tooltips = hover_spec else : tooltips = [ ( col , ( '@' + col ) ) for col in hover_spec ] return tooltips
produce tooltips for column dimensions used in chart configuration .