python 迭代 class 变量并且只获取变量的值

Question

i want an enumerator class which has class variables with same values such as:

from enum import Enum
class Cars(Enum):
  BMW = "BMW"
  Mercedes = "Mercedes"
  Renault = "Renault"

Now i want to iterate over Cars class and get string values of each car as:

for car in Cars:
  print(car)

gives output:

Cars.BMW
Cars.Mercedes
Cars.Renault

to get only string values i need to do:

for car in Cars:
  print(car.value)

But i dont want iterate with .value

i tried to implement __iter__() and __next__() methods but couldn't achieve it.

Answer 1

You can do this by overriding __str__ :

from enum import Enum


class Cars(Enum):
    BMW = "BMW"
    Audi = "Audi"

    def __str__(self):
        return self.value

This isn't really how enum's should be used, though, so I wouldn't recommend it. Just use the colors as the objects they are, and call on .value when you need it. Better yet you can just use .name :

from enum import auto, Enum


class Cars(Enum):
    BMW = auto()
    Audi = auto()


for brand in Cars:
    print(brand.name)