Syntax Error about causalnex HOT 5 CLOSED

from causalnex.structure import StructureModel
# Encoding the causal graph suggested by an expert
#        d
#     ↙  ↓  ↘
#    a ← b → c
#        ↑  ↗
#        e
sm_manual = StructureModel()
sm_manual.add_edges_from(
    
    [
        ("b","a"),
        ("b","c"),
        ("d","a"),
        ("d","c"),
        ("d","b"),
        ("e","c"),
        ("e","b"),
    ],     
    
    
    origin="expert",  
    
)

from causalnex.structure.notears import from_pandas
from causalnex.network import BayesianNetwork
# Unconstrained learning of the structure from data
sm = from_pandas(struct_data)
# Imposing edges that are not allowed in the causal model
sm_with_tabu_edges = from_pandas(struct_data, tabu_edges=[("e", "a")])
# Imposing parent nodes that are not allowed in the causal model
sm_with_tabu_parents = from_pandas(struct_data, tabu_parent_nodes=["a", "c"])
# Imposing child nodes that are not allowed in the causal model
sm_with_tabu_parents = from_pandas(struct_data, tabu_child_nodes=["d", "e"])

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-28-cc0c03133d3a> in <module>
      4 sm = from_pandas(struct_data)
      5 # Imposing edges that are not allowed in the causal model
----> 6 sm_with_tabu_edges = from_pandas(struct_data, tabu_edges=[("e", "a")])
      7 # Imposing parent nodes that are not allowed in the causal model
      8 sm_with_tabu_parents = from_pandas(struct_data, tabu_parent_nodes=["a", "c"])

~/miniconda3/lib/python3.7/site-packages/causalnex/structure/notears.py in from_pandas(X, max_iter, h_tol, w_threshold, tabu_edges, tabu_parent_nodes, tabu_child_nodes)
    241 
    242     if tabu_edges:
--> 243         tabu_edges = [(col_idx[u], col_idx[v]) for u, v in tabu_edges]
    244     if tabu_parent_nodes:
    245         tabu_parent_nodes = [col_idx[n] for n in tabu_parent_nodes]

~/miniconda3/lib/python3.7/site-packages/causalnex/structure/notears.py in <listcomp>(.0)
    241 
    242     if tabu_edges:
--> 243         tabu_edges = [(col_idx[u], col_idx[v]) for u, v in tabu_edges]
    244     if tabu_parent_nodes:
    245         tabu_parent_nodes = [col_idx[n] for n in tabu_parent_nodes]

KeyError: 'e'

from causalnex.structure import StructureModel
import numpy as np
import pandas as pd
from causalnex.structure.notears import from_pandas
from causalnex.plots import plot_structure

a = np.random.normal(0, 1, 200)
b = 5 + 3 * a
c = -6 * a
d = 10 * b
struct_data = pd.DataFrame({"a": a, "b": b, "c": c, "d": d})
sm = from_pandas(struct_data, w_threshold=0.5)
plot_structure(sm)