docstr: Return the variable with data for univariate plots.
docstr_tok: ["Return","the","variable","with","data","for","univariate","plots","."]
code: def data_variable(self):
      """Return the variable with data for univariate plots."""
      # TODO This could also be in core, but it should have a better name.
      if not self.univariate:
          raise AttributeError("This is not a univariate plot")
      return {"x", "y"}.intersection(self.variables).pop()
  
imports: from numbers import Number
  from functools import partial
  import math
  import textwrap
  import warnings
  import numpy
  import pandas
  import matplotlib
  import matplotlib.pyplot
  import matplotlib.transforms
  from matplotlib.cbook import normalize_kwargs
  from matplotlib.colors import to_rgba
  from matplotlib.collections import LineCollection
  from ._base import VectorPlotter
  from ._statistics import ECDF, Histogram, KDE
  from ._stats.counting import Hist
  from .axisgrid import FacetGrid, _facet_docs
  from .utils import remove_na, _get_transform_functions, _kde_support, _check_argument, _assign_default_kwargs, _default_color
  from .palettes import color_palette
  from .external import husl
  from .external.kde import gaussian_kde
  from ._docstrings import DocstringComponents, _core_docs
label_desc: Use image node_id 3 for calling the _DistributionPlotter obj's underlying member method code with example usage: obj.data_variable() and returns: unknown