从类内部访问包含的静态信息的更好/正确的方法

Question

Here is my class:

class node:
    node.maxNum = 10000
    node.maxCoord = 10000.0

    def __init__(self, num = 0, **coordsIn):

        if num > node.maxNum: raise nodeNumException
        self.num = num

        ##set default args##
        coordsDefault = {'X' : float('NaN'), 'Y' : float('NaN')}

        ##set coordinates to input##
        self.coords = coordsIn

        @property.setter
        def coords(self, **Coords):
            for Key in Coords:
                if Coords[Key] > maxCoord: raise nodeCoordException
            ##Set _coords to default, then update from coordsIn##
            self._coords = coordsDefault.update(Coords)
        @property
        def coords(self):
            return self._coords

When creating an instance, the following error is produced:

Traceback (most recent call last):
    File "(stdin)", line 1, in (module)
    File "C:\Projects\CANDE\mesh.py", line 7, in __init__
    if num > node.maxNum: raise nodeNumException
NameError: name 'maxNum' is not defined

I have tried accessing the maxNum and maxCoord variables inside of my class several different ways, but I cannot seem to figure out how to avoid this error.

Is there a way to fix my code and keep the same approach?

Also: is there a better way to do this? Any suggestions would be appreciated. This is my first major Python project.

Answer 1

Class Variables don't require a class qualifier when declaring/defining it. You only need the qualifier when accessing it

class node:
    maxNum = 10000
    maxCoord = 10000.0

    def __init__(self, num = 0, **coordsIn):

        if num > node.maxNum: raise nodeNumException
        self.num = num
        ........

You have more problems in your code

1. When defining the setter, you need a property object.
2. The setter should always follow the getter or else you would get a NameError.

Answer 2

class node:
    maxNum = 10000
    maxCoord = 10000.0

Also change the line to if Coords[Key] > node.maxCoord: raise nodeCoordException , using node to access.

Unrelated but you should use uppercase for class names: class Node