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How to get back name of the enum element?

Tags:

python

enums

I have an enum defined like this:

def enum(**enums):     return type('Enum', (), enums)  Status = enum(        STATUS_OK=0,        STATUS_ERR_NULL_POINTER=1,         STATUS_ERR_INVALID_PARAMETER=2) 

I have a function that returns status as Status enum. How can I get the name of the enum value, and not just value?

>>> cur_status = get_Status() >>> print(cur_status) 1 

I would like to get STATUS_ERR_NULL_POINTER, instead of 1

like image 682
Mike Avatar asked Apr 26 '15 16:04

Mike


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How do I find the class name of an enum?

Description. The java.lang.Enum.name() method returns the name of this enum constant, exactly as declared in its enum declaration.


1 Answers

You'd have to loop through the class attributes to find the matching name:

name = next(name for name, value in vars(Status).items() if value == 1) 

The generator expression loops over the attributes and their values (taken from the dictionary produced by the vars() function) then returns the first one that matches the value 1.

Enumerations are better modelled by the enum library, available in Python 3.4 or as a backport for earlier versions:

from enum import Enum  class Status(Enum):     STATUS_OK = 0     STATUS_ERR_NULL_POINTER = 1      STATUS_ERR_INVALID_PARAMETER = 2 

giving you access to the name and value:

name = Status(1).name  # gives 'STATUS_ERR_NULL_POINTER' value = Status.STATUS_ERR_NULL_POINTER.value  # gives 1 
like image 92
Martijn Pieters Avatar answered Sep 19 '22 21:09

Martijn Pieters