These are functions that help get or set attributes of the data. All of these were basically mapped one-to-one from IDL routines.
pytplot.del_data
pytplot.get_data
pytplot.tplot_copy
pytplot.replace_data
pytplot.get_timespan
pytplot.get_ylimits
pytplot.timebar
pytplot.timespan
pytplot.timestamp
pytplot.tplot_names
pytplot.tplot_rename
pytplot.xlim
pytplot.ylim
pytplot.zlim