class_docstr: Test the JointPlot visualizer without histograms
class_docstr_tok: ["Test","the","JointPlot","visualizer","without","histograms"]
docstr: When self.columns=int or str y must not be None
docstr_tok: ["When","self.columns=int","or","str","y","must","not","be","None"]
code: def test_columns_single_index_no_y(self):
      """
      When self.columns=int or str y must not be None
      """
      oz = JointPlot(columns="foo", hist=False)
      with pytest.raises(
          YellowbrickValueError, match="y must be specified"
      ):
          oz.fit(rand2col(), y=None)
  
imports: import sys
  import pytest
  import numpy
  from functools import partial
  from unittest.mock import patch, MagicMock
  from sklearn.datasets import make_classification, make_regression
  from tests.base import IS_WINDOWS_OR_CONDA, VisualTestCase
  from yellowbrick.exceptions import YellowbrickValueError
  from yellowbrick.features.jointplot import *
  from ..fixtures import Dataset
label_desc: Use image node_id 10 for calling the TestJointPlotNoHistogram obj's underlying member method code with example usage: obj.test_columns_single_index_no_y() without return types