名称错误：未定义名称'\u main\u'

Question

我一直在读这本书，但是我在网上找不到任何解决方法来解决我的问题。我想我的缩进是对的，但是我仍然有名字错误。有人能帮我一下吗。 这个脚本应该在maya中运行一个新的面板，这有点正常，但是这个错误确实很烦人。

class PanelWindow( object ):
    def __init__( self, name, title, namespace=__name__ ):
        self.__name__ = name
        self._title = title
        self.instance = str(namespace) + '.' + self.__name__

        if not pm.scriptedPanelType(self.__name__, q = True, ex = True):
            pm.scriptedPanelType(self.__name__, u = True)

        jobCmd = 'python(\\\"%s._setup()\\\")' % self.instance
        job = "scriptJob -replacePrevious -parent \"%s\" -event \"SceneOpened\" \"%s\";" % ( self.__name__, jobCmd )
        mel.eval(job)

        pm.scriptedPanelType( self.__name__, e = True,
                       unique=True,
                       createCallback = 'python("%s._createCallback()")' % self.instance,
                       initCallback = 'python("%s._initCallback()"  )' % self.instance,
                       addCallback = 'python("%s._addCallback()"   )' % self.instance,
                       removeCallback = 'python("%s._removeCallback()")' % self.instance,
                       deleteCallback = 'python("%s._deleteCallback()")' % self.instance,
                       saveStateCallback = 'python("%s._deleteCallback()")' % self.instance
                        )


    def _setup(self):
        """Command to be call for new scene"""
        panelName = pm.sceneUIReplacement( getNextScriptedPanel=(self.__name__, self._title) )
        if panelName == '':
            try:
                panelName = pm.scriptedPanel( mbv=1, unParent=True, type=self.__name__, label=self._title )
            except:
                pass
        else:
            try:
                label = panel( self.__name__, query=True, label=True )
                pm.scriptedPanel( self.__name__, edit=True,  label=self._title )
            except:
                pass
    def _addCallback(self):
        """Create UI and parent any editors."""
        print 'ADD CALLBACK'
    def show( self ):        
        mel.eval('tearOffPanel "%s" %s true;' % (self._title, self.__name__) )


global test
test = PanelWindow('myName', 'Light')

test.show()


# NameError: name '__main__' is not defined # 
# Error: line 1: name '__main__' is not defined
# Traceback (most recent call last):
#   File "<maya console>", line 1, in <module>
# NameError: name '__main__' is not defined # 

Answer 1

在执行Python脚本时，Python解释器将名为__name__的变量设置为正在执行的模块的字符串值"__main__"（通常此变量包含模块名）。

通常检查此变量的值，以查看您的模块是作为库导入的，还是直接执行的。因此，您经常在模块末尾看到这段代码：

if __name__ == '__main__':
    # do stuff

我怀疑您把字符串引号从'__main__'中去掉了，这就给出了您看到的名称错误

>>> if __name__ == __main__:
...     pass
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name '__main__' is not defined