类名称错误:未定义名称“var" [英] Class NameError: name 'var' is not defined

问题描述

class Gui():
    var = None
    def refreshStats(args):
        print(str(var))
clas = Gui()
clas.refreshStats()

跟踪

File "sample.py", line 5, in refreshStats
    print(str(var))
NameError: name 'var' is not defined.

为什么?

推荐答案

如果您希望您的变量在您的类函数范围内可见，请将 self 传递给每个类函数并将您的类变量用作 self.var 像这样:

If you want your variables to be visible within the scope of your class functions, pass self into every class function and use your class variables as self.var such as this:

class Gui():
    var = None
    def refreshStats(self, args):
        print(str(self.var))
clas = Gui()
clas.refreshStats()

如果您想将其用作实例变量(仅用于类的此实例)而不是类变量(在类的所有实例之间共享)，则应在 __init__ 中声明它代码>功能:

If you want to use this as an instance variable (only for this instance of the class) as opposed to a class variable (shared across all instances of the class) you should be declaring it in the __init__ function:

class Gui():
    def __init__(self):
        self.var = None
    def refreshStats(self, args):
        print(str(self.var))
clas = Gui()
clas.refreshStats()

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