code: def test_patsy_577():
      X = np.random.random((10, 2))
      df = pandas.DataFrame(X, columns=["var1", "var2"])
      from patsy import dmatrix
  
      endog = dmatrix("var1 - 1", df)
      np.testing.assert_(data._is_using_patsy(endog, None))
      exog = dmatrix("var2 - 1", df)
      np.testing.assert_(data._is_using_patsy(endog, exog))
  
imports: import numpy
  import pandas
  from statsmodels.tools import data
label_desc: Use image node_id 3 for calling a global function with example usage: test_patsy_577() without return types