This post originated from an RSS feed registered with Python Buzz by Ben Last. Original Post: __init__ Considered Harmful Feed Title: The Law Of Unintended Consequences Feed URL: http://benlast.livejournal.com/data/rss Feed Description: The Law Of Unintended Consequences Latest Python Buzz Posts Latest Python Buzz Posts by Ben Last Latest Posts From The Law Of Unintended Consequences

class Snapshottable(object):
    """When mixed into an object, provides a way to snapshot the value of some
    or all alltributes into a log.  The log is only created if at least one snapshot is taken."""

    def snapshot(self, attributes=None, note=None):
        """Record the str() values of all attributes in the
        log (or the contents of the object's __dict__ if
        attributes is None.  If note is passed, prepend to
        the log entry."""
        if not attributes:
            attributes = [x for x in self.__dict__.keys() if not x.startswith('__')]

        if note:
            logentry=note+'\n'
        else:
            logentry=''
        for a in attributes:
            if hasattr(self, a):
                logentry += "%s=%s\n" % (a,getattr(self,a))
        try:
            self.log.append(logentry)
        except AttributeError:
            self.log = [logentry]
            
    def getlog(self):
        try:
            return self.log
        except AttributeError:
            self.log = []
            return self.log

    def clearlog(self):
        self.log = []