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Difference between reduce and foldLeft/fold in functional programming (particularly Scala and Scala
...t is both commutative and associative. This means the operation can be parallelized.
This distinction is very important for Big Data / MPP / distributed computing, and the entire reason why reduce even exists. The collection can be chopped up and the reduce can operate on each chunk, then the red...
How do I get the full path to a Perl script that is executing?
...me of the script during execution. I discovered that depending on how you call the script $0 varies and sometimes contains the fullpath+filename and sometimes just filename . Because the working directory can vary as well I can't think of a way to reliably get the fullpath+filename of the scr...
Elegant setup of Python logging in Django
...nowhere else. You can either use a configuration file or do it programmatically step-by-step - it just depends on your requirements. The key thing is that I usually add the handlers I want to the root logger, using levels and sometimes logging.Filters to get the events I want to the appropriate file...
How to retrieve a module's path?
...
import a_module
print(a_module.__file__)
Will actually give you the path to the .pyc file that was loaded, at least on Mac OS X. So I guess you can do:
import os
path = os.path.abspath(a_module.__file__)
You can also try:
path = os.path.dirname(a_module.__file__)
To ge...
UIButton Image + Text IOS
...
I see very complicated answers, all of them using code. However, if you are using Interface Builder, there is a very easy way to do this:
Select the button and set a title and an image. Note that if you set the background instead of the image then the ima...
Why does base64 encoding require padding if the input length is not divisible by 3?
... the protocol used padding, there would be no need to transmit a length at all. The data could be encoded as it came in from the camera, each chunk terminated with padding, and the receiver would be able to decode the stream correctly.
Obviously that's a very contrived example, but perhaps it illus...
If table exists drop table then create it, if it does not exist just create it
...s case than not to cover, see locking note below).
Second RENAME ... atomically replaces table definition, refer to
MySQL manual
for details.
At last, DROP ... just cleans up the old table,
obviously.
Wrapping all statements with something like SELECT GET_LOCK('__upgrade', -1); ... DO RELEASE_LOCK...
Structure padding and packing
....
A note though - unaligned memory access is slower on architectures that allow it (like x86 and amd64), and is explicitly prohibited on strict alignment architectures like SPARC.
share
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improve t...
background function in Python
...em is. I've got a function that downloads the image needed and saves it locally. Right now it's run inline with the code that displays a message to the user, but that can sometimes take over 10 seconds for non-local images. Is there a way I could call this function when it's needed, but run it in t...
Underscore: sortBy() based on multiple attributes
... said, that's pretty hacky. To do this properly you'd probably want to actually use the core JavaScript sort method:
patients.sort(function(x, y) {
var roomX = x[0].roomNumber;
var roomY = y[0].roomNumber;
if (roomX !== roomY) {
return compare(roomX, roomY);
}
return compare(x[0].name...