[Baypiggies] Discussion for newbies/beginner night talks
Shannon -jj Behrens
jjinux at gmail.com
Sat Feb 10 00:51:45 CET 2007
On 2/9/07, Chad Netzer <chad.netzer at gmail.com> wrote:
> First, I want to thank Dennis and Drew for speaking last night, and
> Jim Stockford for hosting the post talk discussion.
> I've created this thread to start discussion about the "newbie" night
> that was talked about at the end of last night's meeting. If people
> reply to this thread only (or mostly), those on the list who aren't
> interested can easily ignore it. If we are to host a beginners night,
> it will be best to start organizing it soon, in order to line up
> topics, speakers, make timely announcements, etc.
> One person at the meeting asked about Python "idioms", and in fact in
> a previous email I brought up the idea of an "anti-idioms"
> presentation. I'll get the ball rolling with a few idioms and tips
> that I can think of, without explanation. If people are interested in
> the why, or wish to add some, please reply and discuss. Perhaps it
> could evolve into a good QA topic for beginners.
> Also, if people have other ideas or suggestions for a beginners night,
> please feel free to discuss them here.
> Some Python beginner tips and idioms:
> 1) Do not use lists, dicts, or any mutable object as default
> arguments; use None instead.
> 2) If you need to do a lot of string appends, use lists and join().
Or use a buffer:
from cStringIO import StringIO
buf = StringIO
> 3) Understand and use iterators in loops.
> 4) Use dictionaries, sets, and other mappings for searches and
> 5) Understand and use the decorate/sort/undecorate (DSU) idiom.
> 6) Catch exceptions that you can handle, don't suppress ones you
> 7) Ask forgiveness, not permission. Ie. perform conversions and
> other operations using "try". Avoid queries to determine if an
> operation will succeed.
> 8) Use assert() to document your code.
> 9) Don't overuse tuples as "read only" lists. Use them to make
> dictionary keys, or pass around short lived groups of objects.
> 10) Use open() to open files, not file(). (trivial, perhaps)
#) Not everything is a class. Some things are just functions. That's
okay. Passing around functions and bound methods is more powerful in
Python than in many non-functional languages.
#) Don't implement the singleton design pattern using a class with a
getInstance method. Modules are implicitly singletons ;)
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