我运行了这段代码，但这不起作用，我使用的是 python 3 btw，我检查了语法一百万次。我已经安装了所有必要的软件包并且它们都是最新的，这是我运行的代码：

from sklearn import tree
features = [[140, 1], [130, 1], [150, 0], [170, 0]]
labels = [0, 0, 1, 1]
clf = tree.DecisionTreeClassifier()
clf = clf.fit(features, labels)
print(clf.predict([[150, 0]]))

这是控制台错误消息（我不知道它到底叫什么，如果你知道请告诉我）：

pydev debugger: starting

Traceback (most recent call last):
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\ptvsd_launcher.py", line 111, in <module>
    vspd.debug(filename, port_num, debug_id, debug_options, run_as)
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\Packages\ptvsd\debugger.py", line 36, in debug
    run(address, filename, *args, **kwargs)
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\Packages\ptvsd\_main.py", line 47, in run_file
    run(argv, addr, **kwargs)
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\Packages\ptvsd\_main.py", line 98, in _run
    _pydevd.main()
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\Packages\ptvsd\pydevd\pydevd.py", line 1628, in main
    globals = debugger.run(setup['file'], None, None, is_module)
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\Packages\ptvsd\pydevd\pydevd.py", line 1035, in run
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\Microsoft\Python\Core\Packages\ptvsd\pydevd\_pydev_imps\_pydev_execfile.py", line 25, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "C:\Users\Sanjay\Documents\python files\SLNforVt\VisualTest\VisualTest.py", line 6
    print(clf.predict([[150, 0]]))
                                  ^
SyntaxError: invalid character in identifier

我在这里使用 Visual Studios，我不知道这是否会影响这个程序，但我也使用 python idle 尝试过。我编写的其他 Python 程序在 Visual Studios 上运行良好，没有任何错误。