我目前要做的项目涉及到从CSV文件中阅读数据，并使用Graphviz来显示数据的可视化表示。这是代码的样子：

import graphviz
import pandas
import os
import math

def save_graph_as_jpg(graph, filename):
    graph.save('temp.dot')
    src = graphviz.Source.from_file('temp.dot')
    src.render(filename, format="jpg")
    os.remove(filename)
    os.remove('temp.dot')

class Node:
    def __init__(self, data, left = None, right = None):
        self.left = left
        self.right = right
        self.data = data

df = pandas.read_csv('decisiontree.csv', index_col = "ID") # df is "data frame"

print(df.to_string())
print(df.info)

nodes = []
nodeMap = {None:None}
for index, row in df[::-1].iterrows():
    row = df.index(int[index])

    if isinstance(df.loc[row][3], float) and math.isnan(df.loc[row][3]):
        df.loc[row][3] = None
    if isinstance(df.loc[row][2], float) and math.isnan(df.loc[row][2]):
        df.loc[row][2] = None
    nodeMap[df.loc[row][0]] = Node(df.loc[row][1],nodeMap[df.loc[row][3]], nodeMap[df.loc[row][2]]), nodes.insert(0,df.loc[row][0])

graph = graphviz.Digraph('structs', filename='structs.gv', node_attr={'shape': 'plaintext', 'ordering':'out'})
        
for nodeID in nodes:
    node = nodeMap[nodeID]
    if node.left:
        graph.edge(node.data, node.left.data)
    if node.right:
        graph.edge(node.data, node.right.data)

save_graph_as_jpg(graph, "Decisiontree")

当我用IDLE运行它时，它返回的大部分代码都很好，但是在第27行挂起了：

row = df.index(int[index])

我收到一条追溯消息，内容如下：

Traceback (most recent call last):
  File "C:\Users...... line 27, in <module>
    row = df.index[index]
  File "C:\Users......Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\pandas\core\indexes\base.py", line 5382, in __getitem__
    result = getitem(key)
IndexError: only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices

我把它改成了：

row = df.index(int[index])

现在我得到了一个回溯和索引错误：

Traceback (most recent call last):
  File "C:\Users.......CTML AI\Week 3\Lab3.py", line 27, in <module>
    row = df.index(int[index])
TypeError: 'type' object is not subscriptable