关于python的ctypes结构体引用问题

[careysucci]

class MOUSEINPUT(Structure):
    _fields_ = [
        ('dx',LONG),
        ('dy',LONG),
        ('mouseData',DWORD),
        ('dwFlags',DWORD),
        ('time',DWORD),
        ('dwExtraInfo',ULONG_PTR)
    ]

class INPUT(Structure):
    class KEY(Union):
        _fields_ = [
            ('mi',MOUSEINPUT),
            ('ki',KEYBDINPUT),
            ('hi',HARDWAREINPUT)
            ]
    _anonymous = ('key',)
    _fields_ = [
        ('type',DWORD),
        ('key',KEY)
    ]

在嵌套INPUT结构体中引用MOUSEINPUT，编译时，编译器提示：NameError: name 'MOUSEINPUT' is not defined
请问错在哪里，这两段代码都在同一个文件里

[惟愿莲心不染尘]

同 1L 问

[panghuhu250]

MOUSEINPUT的定义在INPUT的定义之前？