python - 在为全局变量赋值之前引用的局部变量“删除”

Question

我在项目开始时设置了一个全局变量 delete ，就在导入的库下方和任何类之前，但是当我有这段代码时：

def motion_notify_callback(event):
        if (ispymol == True):

            if event.inaxes is ax:      
            x = event.xdata
            y = event.ydata
            x = round(x,0)
            y = round(y,0)
            x = int(x)
            y = int(y)
            coord = (x,y)


            for i in range(0,len(number_list)):

                if (coord == number_list[i]):
                if (delete == True):
                    pymol.cmd.do("delete CurrentCont")
                    delete = False
                pymol.cmd.do("distance CurrentCont, chain"+lc+" and resi "+resi1[i]+" and name CA, chain"+lc+" and resi "+resi2[i]+" and name CA")

                    delete = True

            for i in range(0,len(rres)):
            if (coord == mappingpredcont[i]):
               if (delete == True):
                       pymol.cmd.do("delete CurrentCont")
                       delete =False
               pymol.cmd.do("distance CurrentCont, chain"+lc+" and resi "+predresi1[i]+" and name CA, chain"+lc+" and resi "+predresi2[i]+" and name CA")

                   delete = True

它在为全局变量赋值之前引用了错误局部变量“删除”我哪里出错了？

Answer 1

你需要告诉 Python 你打算分配给一个全局变量：

def motion_notify_callback(event):
    global delete
    ...

Answer 2

您需要在函数的开头定义delete为 a ：global

def motion_notify_callback(event):
   global delete
   .....