[Omaha.pm] Re: [oma-python] mapping lambdas and other things
Jay Hannah
jay at jays.net
Sun Jun 13 22:08:10 CDT 2004
On Jun 13, 2004, at 1:22 PM, thehaas at binary.net wrote:
> On Fri, Jun 11, 2004 at 08:39:46PM -0500, Jay Hannah wrote:
>>
>> On Jun 10, 2004, at 6:30 AM, Mike Hostetler wrote:
>>> Here is an example of real working code that decodes a list of
>>> Unicode
>>> strings into latin-1:
>>> goodProcRef = map(lambda x: x.decode("latin-1"), goodProcRef)
>>
>> How do you use that? (Can I get some context code?)
>
> The map function applies a function to every item in a list, returning
> of list of the result. You can do the same thing with a for-loop, but
> using the map function is much faster.
>
> In Perl, it would be something like:
>
> @decoded = [];
> for $p in (@goodProcRef) {
> push(@decoded,$p->decode());
> }
> @goodProcRef=@decoded;
Ah. Thanks. Perl has a map function too, BTW (perldoc -f map). I didn't
realize Python's map does the exact same thing. for loops also create
references to each element in an array and place it in the default
variable $_, so you can do things like
for (@objects) { $_->decode("latin-1") }
or
for (@strings) { s/foo/bar/ }
Ooo... I just discovered "pydoc map"...
j
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