Referrer key missing form os.environ dictionary?

[Νίκος]

Στις 25/9/2013 5:01 μμ, ο/η Chris “Kwpolska” Warrick έγραψε:
> On Wed, Sep 25, 2013 at 2:45 PM, Νίκος <nikos.gr33k at gmail.com> wrote:
>> Hello, i decided am ong other os.environ variables to also grab the
>> 'HTTP_REFERER' fiel but when i try to run my script i was seeing a KeyError
>> complaining that 'HTTP_REFERER' didnt exist.
>>
>> So, to see what existed in the os.environ dictionary i issues a print(
>> os.environ ) to see all available keys and their values:
>
> The Referer header is not mandatory by any means.  Your client
> probably does not send it.
>
But one other problem appeared too:

nikos at superhost.gr [~/www/cgi-bin]# python metrites.py
   File "metrites.py", line 27
     host = socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0] or 
'UnKnown Host'
        ^
SyntaxError: invalid syntax


i dont see anything wrong with that line, and the carret is actually 
pointing to the "host".