Question

我已经定义了一些类：

class CustomParameter():
    def __init__(self, strFriendlyAttribName, strSystemAttribName):
        self.FriendlyAttribName = strFriendlyAttribName
        self.SystemAttribName = strSystemAttribName

class PartMaster():
    AttribNameList = ["Part Number", "Name", "Standard Part", "Part Type", "ControlledBy", "PIN", "Design Responsibility"]

    def __init__(self):
        self._UUID = None

        self.PartNumber = CustomParameter("Part Number", "V_ID"),
        self.Name = CustomParameter("Name", "V_name"),
        self.StandardPart = CustomParameter("Standard Part", "V508_isStandardPart"),
        self.PartType = CustomParameter("Part Type", "V511_PartType"),
        self.ControlledBy = CustomParameter("ControlledBy", "V511_ControlledBy"),
        self.PIN = CustomParameter("PIN", "BOECACPinItemNumber"),
        self.DesignResponsibility = CustomParameter("Design Responsibility", "BOECACDesignRpnse")

class Part():
    def __init__(self, PartNumber):

        self.PartNumber = PartNumber

        #This instance wraps
        self.PartMaster = PartMaster() #create new instance



test = Part("ABC")

我希望test.PartMaster.PIN是CustomParameter的一个实例，但它是一个元组tuple: (<__main__.CustomParameter instance at 0x0000000002D724C8>,)为什么会这样，我怎么能不这样做呢？

我想构建我的类，以便test.PartMaster.PIN向我提供我的CustomParameter类的实例实例。有什么想法吗？

Answer 1

因为您的类初始化时，PartMaster类的实例变量在末尾设置了逗号：）

Python解释了这一点：

x = 'test',

为：

('test',)

请改为尝试：

def __init__(self):
    self._UUID = None

    self.PartNumber = CustomParameter("Part Number", "V_ID")
    self.Name = CustomParameter("Name", "V_name")
    self.StandardPart = CustomParameter("Standard Part", "V508_isStandardPart")
    self.PartType = CustomParameter("Part Type", "V511_PartType")
    self.ControlledBy = CustomParameter("ControlledBy", "V511_ControlledBy")
    self.PIN = CustomParameter("PIN", "BOECACPinItemNumber")

这发生在我身上很多次。每当我从写出大量字典切换到在这样的类中设置变量时，我总是忘记逗号。但是把头发拉过来一次，你就会知道要找什么！

为什么我的嵌套python类实例成为元组？

1 个答案: