Order of addresses returned by socket.gethostbyname_ex()

[Roy Smith]

In article 
<034ff4bf-e3e4-47ff-9a6c-195412431e73 at s20g2000yql.googlegroups.com>,
 Tomas Lidén <tomas.liden.privat at gmail.com> wrote:

> Basically I was asking about the contract for this method.. hoping
> that it is deterministic.

The contract for socket.gethostbyname_ex() is described at 
http://docs.python.org/library/socket.html#socket.gethostbyname_ex.  It 
says:

"Translate a host name to IPv4 address format, extended interface. 
Return a triple (hostname, aliaslist, ipaddrlist) where hostname is the 
primary host name responding to the given ip_address, aliaslist is a 
(possibly empty) list of alternative host names for the same address, 
and ipaddrlist is a list of IPv4 addresses for the same interface on the 
same host (often but not always a single address). gethostbyname_ex() 
does not support IPv6 name resolution, and getaddrinfo() should be used 
instead for IPv4/v6 dual stack support."

That's it.  It says nothing about ordering, so nothing about ordering 
should be inferred.

> Our testing indicated that the interfaces are returned in a specific
> order, but we want to know if this is really the case (on all
> platforms).

No, it is not.