Python-MacOSX中graphviz模块遇到的问题

当我尝试使用

graphviz

模块查看

a
.dot
文件时，出现以下错误：

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/backend.py", line 158, in run
    proc = subprocess.Popen(cmd, startupinfo=get_startupinfo(), **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/subprocess.py", line 775, in `__init__`
    restore_signals, start_new_session)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/subprocess.py", line 1522, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'dot': 'dot'

在处理上述异常期间，发生了另一个异常：

Traceback (most recent call last):
  File "/Users/user_name/Desktop/New code folder September 7 2019/Introduction to machine learning/ch2_0002.py", line 118, in <module>
    test_cancer_pre_pruning()
  File "/Users/user_name/Desktop/New code folder September 7 2019/Introduction to machine learning/ch2_0002.py", line 109, in test_cancer_pre_pruning
    graphviz.Source(dot_graph).view()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/files.py", line 242, in view
    quiet=quiet, quiet_view=quiet_view)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/files.py", line 209, in render
    quiet=quiet)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/backend.py", line 205, in render
    run(cmd, capture_output=True, cwd=cwd, check=True, quiet=quiet)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/backend.py", line 161, in run
    raise ExecutableNotFound(cmd)
graphviz.backend.ExecutableNotFound: failed to execute ['dot', '-Tpdf', '-O', 'Source.gv'], make sure the Graphviz executables are on your systems' PATH

回溯（最近一次呼叫最后一次）：
文件“/Users/user_name/Desktop/New code folder 2019年9月7日/Introduction to machine learning/ch2_0002.py”，第118行，在
test_cancer_pre_修剪（）
文件“/Users/user\u name/Desktop/New code folder 2019年9月7日/Introduction to machine learning/ch2\u 0002.py”，第109行，测试前剪枝
graphviz.Source（dot_graph.view）（）
文件“/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site packages/graphviz/files.py”，第242行，在视图中
安静=安静，安静\u视图=安静\u视图）
文件“/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site packages/graphviz/files.py”，第209行，在渲染中
安静=安静）
文件“/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site packages/graphviz/backend.py”，第205行，在render中
运行（cmd，capture_output=True，cwd=cwd，check=True，quiet=quiet）
文件“/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site packages/graphviz/backend.py”，第161行，正在运行
raise ExecutableNotFound（cmd）
graphviz.backend.ExecutableNotFound:未能执行['dot'、'-Tpdf'、'-O'、'Source.gv']，请确保graphviz可执行文件位于系统的路径上

我试过：


pip3安装graphviz
康达安装graphviz

两者似乎都没有解决问题。
可能
dot
不在您的路径中。如何解决此问题？请检查您的路径变量。检查是否可以从命令行（
dot-V
）启动dot，以防无法将其添加到path变量中。