python - 在成员函数中传递同一类的实例会引发 Class not found NameError

Question

我正在尝试将类的实例传递给同一类的成员函数，例如：

class LatLong():
    def __init__(self, lat, long):
        self.lat = float(lat)
        self.long = float(long)
    def distance_to(self, latLong: LatLong):
        pass

我得到类未定义错误：

<ipython-input-5-139f9b0f07a2> in LatLong()
      3         self.lat = float(lat)
      4         self.long = float(long)
----> 5     def distance_to(self, latLong: LatLong):
      6         pass

NameError: name 'LatLong' is not defined

如果不可能，我该如何应用类型约束？

标签： pythonclasstypes