Checking if a Variable Exists in Python - Doesn't work with self

Question

Before you down rep this post, it hasn't been asked anywhere that I can find.

I'm checking for the existence of a list by using

if 'self.locList' in locals():
    print 'it exists'

But it doesn't work. It never thinks it exists. This must be because I'm using inheritance and the self. to reference it elsewhere, I don't understand what's happening.

Can anyone shed some light please?

Here is the full code:

import maya.cmds as cmds

class primWingS():
    def __init__(self):
        pass
    def setupWing(self, *args):
        pass
    def createLocs(self, list):
        for i in range(list):
    if 'self.locList' in locals():
        print 'it exists'
            else:
                self.locList = []
            loc = cmds.spaceLocator(n = self.lName('dummyLocator' + str(i + 1) + '_LOC'))
            self.locList.append(loc)
            print self.locList


p = primWingS()

Answer 1

I think you want hasattr(self,'locList')

Although, you're usually better off trying to use an attribute and catching the AttributeError which gets raised if it isn't present:

try:
    print self.locList
except AttributeError:
    self.locList = "Initialized value"