Question

Is there a better way to write this code? I know it’s very simple, but the way I wrote it seems so repetitive.

I’m not necessary looking for a one-line genius code, just some other readable, useful alternative.

Thanks in advance!

def __unicode__( self ):
    location = []

    if self.room != None:
        location.append( self.room )
    if self.floor != None:
        location.append( self.floor )
    if self.building != None:
        location.append( self.building )

    location.append( self.property )

    return ", ".join( location )

self.property is always set, which is not true for self.room, self.floor, and self.building. By the way, this is part of the models.py of a Django code in case anyone is wondering.

Side question: Is using property as a variable name a bad idea? I noticed property gets highlighted under syntax, but I looked it up and it’s not a Python reserved word.

Here is the complete class:

class Location( models.Model ):
    def __unicode__( self ):
        location = []

        if self.room != None:
            location.append( self.room )
        if self.floor != None:
            location.append( self.floor )
        if self.building != None:
            location.append( self.building )

        location.append( self.property )

        return ", ".join( location )

    comments   = models.TextField( blank = True )
    room       = models.CharField( max_length = 135, blank = True )
    floor      = models.CharField( max_length = 135, blank = True )
    building   = models.CharField( max_length = 135, blank = True )
    property   = models.ForeignKey( Property )
    t_created  = models.DateTimeField( auto_now_add = True )
    t_modified = models.DateTimeField( auto_now = True )

Answer 1

This first part was an answer to the original question if choosing the first non-None element to append. See updates below that address the revised question

Without trying to do a crazy one-line or something too fancy, I think this is a pretty easy solution. Just loop over them and append the first one that is not None, then break.

for loc in (self.room, self.floor, self.building):
    if loc is not None:
        location.append(loc)
        break

If you want a one-liner, here is a list comprehension:

location = [l for l in (self.room, self.floor, self.building) if l is not None][:1]

A more readable compromise to that last one could be:

options = (self.room, self.floor, self.building)
location = [l for l in options if l is not None][:1]

@tzaman was right in suggesting not to use property for your variable names. It is a built in type:

>>> property
<type 'property'>

class property(object)
 |  property(fget=None, fset=None, fdel=None, doc=None) -> property attribute
 |  
 |  fget is a function to be used for getting an attribute value, and likewise
 |  fset is a function for setting, and fdel a function for del'ing, an
 |  attribute.  Typical use is to define a managed attribute x:

Update

Because in your comments you mentioned what you actually wanted was any of those properties that are not None, its a super simple list comp:

locations = [l for l in (self.room, self.floor, self.building) if l is not None]

Update 2: A great suggestion in the comments by @Vaughn Cato

locations = filter(None, [self.room, self.floor, self.building])