在路径中找不到“.dot” - 将 PATH 添加到 Windows 环境变量后答案

【问题标题】：".dot" not found in path - After adding PATH to Windows Environment variables在路径中找不到“.dot” - 将 PATH 添加到 Windows 环境变量后
【发布时间】：2019-08-28 23:13:45
【问题描述】：

我正在尝试使用 Graphviz2 可视化随机森林。我正在使用的代码如下所示。但是，当我尝试读取 .dot 文件时，会出现以下错误：

FileNotFoundError: [WinError 2] "dot" not found in path

我看到其他人遇到这个错误并通过修改 Windows 环境变量来解决它。我在 PATH 中添加了以下内容：

C:\Program Files (x86)\Graphviz2.38\bin;
C:\Program Files (x86)\Graphviz2.38\;
C:\Users\Adarsh\Anaconda3\Lib\site-packages\graphviz

这些都不行。

import pickle
filename = '11f_rf_roc91.sav'
loaded_model = pickle.load(open(filename, 'rb'))

import os
from sklearn.tree import export_graphviz
import six
import pydot
from sklearn import tree
dotfile = six.StringIO()
i_tree = 0
for tree_in_forest in loaded_model.estimators_:
    export_graphviz(tree_in_forest, out_file='tree.dot', feature_names = list(X), class_names = ["0", "1"], rounded = True, proportion = False, precision = 2, filled = True)
    (graph,) = pydot.graph_from_dot_file('tree.dot')
    name = 'tree' + str(i_tree)
    graph.write_png(name+  '.png')
    os.system('dot -Tpng tree.dot -o tree.png')
    i_tree +=1

【问题讨论】：

标签： python-2.7 path tree random-forest

【解决方案1】：

上述路径都可以。您的 dot_data 文件本身存在问题。为了清楚起见，也请参阅内联 cmets。

#这里所有的import语句都按照Python PEP约定。

import os
import pydot
import pickle

from sklearn import tree
from sklearn.tree import export_graphviz     # this can be even > import export_graphviz <
from sklearn.externals.six import StringIO   # shortened StringIO instead of six.StringIO

filename = '11f_rf_roc91.sav'
loaded_model = pickle.load(open(filename, 'rb'))

dot_data = StringIO()          # this is data not filename "dotfile".
i_tree = 0

for tree_in_forest in loaded_model.estimators_:
    export_graphviz(tree_in_forest, 
                    out_file      = dot_data,    # now linked to correct file data
                    feature_names = list(X),     # X seems not to be defined.
                    class_names   = ["0", "1"], 
                    rounded       = True, 
                    proportion    = False, 
                    precision     = 2, 
                    filled        = True)

    graph = pydot.graph_from_dot_file(dot_data)
    name = 'tree' + str(i_tree)
    graph.write_png(name+  '.png')
    os.system('dot -Tpng tree.dot -o tree.png')
    i_tree += 1

【讨论】：