Backported WatchedFileHandler for python2.4 (copy-paste from python 2.6 standard library). Did some minor testing it should work as drop in replacement.

log_handlers.py

from stat import ST_DEV, ST_INO
import logging
import os


try:
    import codecs
except ImportError:
    codecs = None


class WatchedFileHandler(logging.FileHandler):
    """
    A handler for logging to a file, which watches the file
    to see if it has changed while in use. This can happen because of
    usage of programs such as newsyslog and logrotate which perform
    log file rotation. This handler, intended for use under Unix,
    watches the file to see if it has changed since the last emit.
    (A file has changed if its device or inode have changed.)
    If it has changed, the old file stream is closed, and the file
    opened to get a new stream.

    This handler is not appropriate for use under Windows, because
    under Windows open files cannot be moved or renamed - logging
    opens the files with exclusive locks - and so there is no need
    for such a handler. Furthermore, ST_INO is not supported under
    Windows; stat always returns zero for this value.

    This handler is based on a suggestion and patch by Chad J.
    Schroeder.
    """
    def __init__(self, filename, mode='a', encoding=None, delay=0):
        # NOTE: seems python before v2.6 doesn't set self.encoding
        if codecs is None:
            encoding = None
        self.encoding = encoding
        logging.FileHandler.__init__(self, filename, mode, encoding)
        if not os.path.exists(self.baseFilename):
            self.dev, self.ino = -1, -1
        else:
            stat = os.stat(self.baseFilename)
            self.dev, self.ino = stat[ST_DEV], stat[ST_INO]

    def emit(self, record):
        """
        Emit a record.

        First check if the underlying file has changed, and if it
        has, close the old stream and reopen the file to get the
        current stream.
        """
        if not os.path.exists(self.baseFilename):
            stat = None
            changed = 1
        else:
            stat = os.stat(self.baseFilename)
            changed = (stat[ST_DEV] != self.dev) or (stat[ST_INO] != self.ino)
        if changed and self.stream is not None:
            self.stream.flush()
            self.stream.close()
            self.stream = self._open()
            if stat is None:
                stat = os.stat(self.baseFilename)
            self.dev, self.ino = stat[ST_DEV], stat[ST_INO]
        logging.FileHandler.emit(self, record)

    # NOTE: copy this from python v2.6 std lib
    # seems python before v2.6 doesn't have this
    def _open(self):
        """
        Open the current base file with the (original) mode and encoding.
        Return the resulting stream.
        """
        if self.encoding is None:
            stream = open(self.baseFilename, self.mode)
        else:
            stream = codecs.open(self.baseFilename, self.mode, self.encoding)
        return stream