Order a list to get a hierarchical order

[Thibaut DIRLIK]

Hi,

Having a list of objet with a parent_id attribute pointing to a parent, I
want to order this list like this :

[Parent #1, Child #1.1, Child#1.1.1, Child#1.1.2, Child#1.2, Parent #2,
Child #2.1, ...]

Any clue on how to do this ?

Thanks,
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Order a list to get a hierarchical order

[Thibaut DIRLIK]

Thanks for your help, I'll test this.

2012/6/8 Peter Otten __pete...@web.de

 Ivars Geidans wrote:

  def append_node(n, l, ls):
  ls.append(n)
  for c in [nc for nc in l if nc.parent is n]:
  append_node(c, l, ls)
  return ls
 
  def sort_nodes(l):
  ls = []
  for r in l:
  if r.parent == None:
  append_node(r, l, ls)
 
  return ls

 This ensures that child nodes appear after their parent but leaves the
 order
 of nodes on the same level undefined. I think adding

 def sort_nodes(l):
  l = sorted(l, key=lambda node: node.name) #untested
  ...

 would fix that.

 --
 http://mail.python.org/mailman/listinfo/python-list

-- 
http://mail.python.org/mailman/listinfo/python-list

Working with dates : complex problem

[Thibaut DIRLIK]

Hi,

I've a list of python objects with dates attributes. This list is ordered
by one of these date. Elements mandatory follow each other :

Element #1   Element #2   Element #3
|-|--|--|

Now, I want to insert an element in this timeline. This imply that I will
have to resize some elements :

Element #1   Element #2   Element #3
|-|--|--|
New element
  |--|

And after resize :

Element #1  New element   Element #2   Element #3
|-|--|-|--|

  |--|

My question is the following : how can I know (easily) which elements my
New element is over, which,
in my example would have returned ['Element #1', 'Element #2'].

Elements objets are simple Python objects with dates :

obj.begin = datetime()
obj.end = datetime()

I'm looking for the more Pythonic way to handle this problem, thanks !
-- 
http://mail.python.org/mailman/listinfo/python-list

Sockets accept() in child processes

[Thibaut DIRLIK]

Hi,

I'm writing a multiprocess server with Python 3.2 and the multiprocessing
module. Here is my current implementation :

- Main process: select() on a list of server sockets (different ips of the
host, ssl or not, etc)
- Children process : When they get a signal (in fact, a message in a pipe),
they will accept() the server socket

The problem is that after select() returns, I can accept() in the main
process, but in a children process I got a EAGAIN error.
The sockets are non-blocking. It seems that accept() can only be called in
the same process that the one which selected().

This is a problem because I wanted to decide which process I should ask
to take the connection
to do some basic load-balacing based on current number of connected client
in each process.

Could someone help me or propose other implementations ?

Thank you,
-- 
http://mail.python.org/mailman/listinfo/python-list

Multiprocessing Logging

[Thibaut DIRLIK]

Hi,

I'm currently writing a multiprocess applications with Python 3.2 and
multiprocessing module. My subprocesses will use a QueueHandler to log
messages (by sending them to the main process, which uses a QueueListener).
However, if logging is already configured when I create the subprocesses,
they will inherit the configuration, and opened file descriptors used for
logging in the main process.

However, when I tried this with a basicConfig configuration, which prints
to a file, the messages are only written once to the file. I don't
understand why. Normally, the mainprocess contains a logging handler to log
to the file. This handler will be copied into the child processes. Child
processes will then have two handlers : a QueueHandler, and a FileHandler.
They should write to the file handler and then send the message to the main
process QueueListener, which should write the message AGAIN to the
FileHandler.

But that's not the case. Any rea

How can I totally unset the logging configuration in child processes and
only enable the QueueHandler (foor all configured loggers, not only the
root one) ?

Thanks for your help,
-- 
http://mail.python.org/mailman/listinfo/python-list