plot_structure does not plot anything about causalnex HOT 2 CLOSED

from IPython.display import Image
from causalnex.plots import plot_structure, NODE_STYLE, EDGE_STYLE

viz = plot_structure(
    sm,
    graph_attributes={"scale": "0.5"},
    all_node_attributes=NODE_STYLE.WEAK,
    all_edge_attributes=EDGE_STYLE.WEAK)
filename = "./structure_model.png"
viz.draw(filename)
Image(filename)

data = pd.read_csv('../data/student-por.csv', delimiter=';')
drop_col = ['school','sex','age','Mjob', 'Fjob','reason','guardian']
data = data.drop(columns=drop_col)
struct_data = data.copy()

non_numeric_columns = list(struct_data.select_dtypes(exclude=[np.number]).columns)
print(non_numeric_columns)

le = LabelEncoder()
for col in non_numeric_columns:
    struct_data[col] = le.fit_transform(struct_data[col])
    
sm = from_pandas(struct_data)
_, _, _ = plot_structure(sm)

/usr/local/lib/python3.7/site-packages/pygraphviz/agraph.py:1367: RuntimeWarning: Warning: node 'address', graph '%3' size too small for label
Warning: node 'famsize', graph '%3' size too small for label
Warning: node 'Pstatus', graph '%3' size too small for label
Warning: node 'Medu', graph '%3' size too small for label
Warning: node 'Fedu', graph '%3' size too small for label
Warning: node 'traveltime', graph '%3' size too small for label
Warning: node 'studytime', graph '%3' size too small for label
Warning: node 'failures', graph '%3' size too small for label
Warning: node 'schoolsup', graph '%3' size too small for label
Warning: node 'famsup', graph '%3' size too small for label
Warning: node 'paid', graph '%3' size too small for label
Warning: node 'activities', graph '%3' size too small for label
Warning: node 'nursery', graph '%3' size too small for label
Warning: node 'higher', graph '%3' size too small for label
Warning: node 'internet', graph '%3' size too small for label
Warning: node 'romantic', graph '%3' size too small for label
Warning: node 'famrel', graph '%3' size too small for label
Warning: node 'freetime', graph '%3' size too small for label
Warning: node 'goout', graph '%3' size too small for label
Warning: node 'Dalc', graph '%3' size too small for label
Warning: node 'Walc', graph '%3' size too small for label
Warning: node 'health', graph '%3' size too small for label
Warning: node 'absences', graph '%3' size too small for label
Warning: node 'G1', graph '%3' size too small for label
Warning: node 'G2', graph '%3' size too small for label
Warning: node 'G3', graph '%3' size too small for label

  warnings.warn(b"".join(errors).decode(self.encoding), RuntimeWarning)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-7-d2da9edb9d84> in <module>
---->  _, _, _ = plot_structure(sm)

ValueError: too many values to unpack (expected 3)