Using classes to keep predefined strings

Question

Is that a good way to define a class like this:

class states:
    INACTIVE = 'Inactive'
    ACTIVE = 'Active'
    PENDING = 'Pending'
    BANNED = 'Banned'

to keep a list of possible values and then get them as, e.g. states.INACTIVE, so when I want to change user's status, I do something like this: user.status=states.BANNED and it gets value 'Banned'. I use it to quickly access these values with IntelliSense in my IDE with ctrl-space and it also makes it safer against typos. Though, I am not sure it's a good approach to create a class for just keeping some strings. How can I organize it a better way or is that a good solution?

score 4 · Accepted Answer · answered Apr 13 '11 at 14:07

I think this solution is OK. But maybe I would add those constants to the user class:

class User:
    STATUS_INACTIVE = 'Inactive'
    STATUS_ACTIVE = 'Active'
    STATUS_PENDING = 'Pending'
    STATUS_BANNED = 'Banned'

    def __init__(self):
        self.status = User.STATUS_ACTIVE

score 1 · Answer 2 · edited May 23 '17 at 12:23

1

It seems like what you want is an enumeration.

edited May 23 '17 at 12:23

Community

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answered Apr 13 '11 at 14:10

nmichaels

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jathanism · Answer 3 · 2011-04-13T18:16:04.120

You could also provide these as module-level variables in a distinct states module:

# states.py
INACTIVE = 'Inactive'
ACTIVE = 'Active'
PENDING = 'Pending'
BANNED = 'Banned'

And then import states in your code:

# example.py
import states

# ... stuff happens to create user instance
user.status = states.BANNED

With this method there is no need to instantiate a class just to pull variables from it. I have no idea whether or not this is the most efficient route, but it is very convenient.

score 1 · Answer 4 · answered Apr 13 '11 at 14:28

1

I am using this at number of places. And think it is perfectly ok.

answered Apr 13 '11 at 14:28

Shekhar

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Using classes to keep predefined strings

4 Answers4