Skip to main content

DeferArgs 0.3 by Example

DeferArgs 0.3, just a few hours after 0.2, is now released here. The only update is support for attemp/catch-all blocks without any @catch(type) handlers. In response to some people in #twisted@irc.freenode.net, here are examples that show what can be done more clearly.

To write any function that can accept deferred arguments nicely:

@deferargs
def printArgs(*args, **kwargs):
print args
print kwargs


To add psuedo-exception handlers and a psuedo-finally block to a @deferargs decorated function:

@deferargs
def printArgs(*args, **kwargs):
print args
print kwargs
print "This one is important! ", kwargs['important']
@catch(KeyError)
def onKeyError(e):
print "There was no important kwarg!"
@catch()
def onAnyError(e):
print "Crap!"
@cleanup()
def _(r):
print "Every thing is done."


There is also a model for a psuedo-try block, which basically decorates just calls the function immediately when you define it and its catch/cleanup handlers:

@attempt
def this():
assert False
@cleanup
def _(r)
print "And thats it."

Comments

Popular posts from this blog

Why I Switched From Git to Microsoft OneDrive

I made the unexpected move with a string of recent projects to drop Git to sync between my different computers in favor of OneDrive, the file sync offering from Microsoft. Its like Dropbox, but "enterprise."

Feeling a little ashamed at what I previously would have scoffed at should I hear of it from another developer, I felt a little write up of the why and the experience could be a good idea. Now, I should emphasize that I'm not dropping Git for all my projects, just specific kinds of projects. I've been making this change in habit for projects that are just for me, not shared with anyone else. It has been especially helpful in projects I work on sporadically. More on why a little later.

So, what drove me away from Git, exactly?

On the smallest projects, like game jam hacks, I just wanted to code. I didn't want to think about revisions and commit messages. I didn't need branching or merges. I didn't even need to rollback to another version, ever. I just …

Respect and Code Reviews

Code Reviews in a development team only function best, or possible at all, when everyone approaches them with respect. That’s something I’ve usually taken for granted because I’ve had the opportunity to work with amazing developers who shine not just in their technical skills but in their interpersonal skills on a team. That isn’t always the case, so I’m going to put into words something that often exists just in assumptions.
You have to respect your code. This is first only because the nature and intent of code reviews are to safeguard the quality of your code, so even having code reviews demonstrates a baseline of respect for that code. But, maybe not everyone on the team has the same level of respect or entered a team with existing review traditions that they aren’t acquainted with.
There can be culture shock when you enter a team that’s really heavy on code reviews, but also if you enter a team or interact with a colleague who doesn’t share that level of respect for the process or…

CARDIAC: The Cardboard Computer

I am just so excited about this.


CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer. 
One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC?

It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operate on. The only re…