Pep8建议始终cls
用作类方法定义的第一个参数。现在假设我想使用一个类变量(在这种情况下:)cls.cartridge_state
,它也可以在实例方法中使用(在这种情况下:)__init__
。所以为此我需要使变量成为全局变量(参见下面的代码)。但是实例化FountainPen
会产生以下运行时错误:
self.cartridge_state = cls.cartridge_state
NameError: global name 'cls' is not defined
但是当我更改global cartridge_state
为global cls.cartridge_state
我尝试导入模块时再次收到 syntaxError 。
class FountainPen(object):
cartridge_ink = "water-based"
@classmethod
def toggle_default_cartridge_state(cls):
i = 0
cartridge_states = ['non-empty','empty']
global cartridge_state
cls.cartridge_state = cartridge_states[i]
i += 1
def __init__(self):
self.cartridge_state = cls.cartridge_state
global number_of_refills
self.number_of_refills = 0
def write(self):
print Pen.write(self)
self.cartridge_state = "empty"
return self.cartridge_state
def refill(self):
self.cartridge_state = "non-empty"
self.number_of_refills += 1
如何让类变量cartridge_state
符合 pep8 并使此代码正常工作?