I have two questions about the observer pattern in Python.
This is question #1. (I'll put the other is a separate post.)
Here is a standard example of the observer pattern in Python:
http://en.wikipedia.org/wiki/Observer_pattern
Contrast with this rather standard discussion:
Alan Isaac [EMAIL PROTECTED] writes:
Is anything lost by not maintaining this reference (other
than error checking ...)? If I feel the observer needs
access to the subject, what is wrong with just having the
subject pass itself as part of the notification?
It reduces the number of
Alan Isaac [EMAIL PROTECTED] writes:
Is anything lost by not maintaining this reference (other
than error checking ...)? If I feel the observer needs
access to the subject, what is wrong with just having the
subject pass itself as part of the notification?
Ville M. Vainio
Alan Isaac [EMAIL PROTECTED] writes:
the following: OK, here's the pattern, now your listener
wants to know the event source, do not ask something new the
subject to respond to that need. That is unnecessary
coupling. Instead, just rewrite your listener to maintain
a reference to the
Ville M. Vainio wrote:
in case of stocks, you are probably monitoring several
stock objects, so the stock should probably pass itself to
the observer
OK. This is related to my question #2 (in a separate
thread), where I'd also appreciate your comments.
analogous to a typical
On May 8, 4:57 pm, Alan Isaac [EMAIL PROTECTED] wrote:
Ville M. Vainio wrote:
in case of stocks, you are probably monitoring several
stock objects, so the stock should probably pass itself to
the observer
OK. This is related to my question #2 (in a separate
thread), where I'd also
