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Match multiple cases classes in scala
... matcher(l: Foo): String = {
l match {
case A() => "A"
case B(_) | C(_) => "B"
case _ => "default"
}
}
If you must, must, must extract the parameter and treat them in the same code block, you could:
def matcher(l: Foo): String = {
l match {
case A() => "A"
ca...
difference between foldLeft and reduceLeft in Scala
...e between reducing and folding
The difference is not the implementation at all, just look at the signatures.
The question doesn't have anything to do with Scala in particular, it's rather about the two concepts of functional programming.
Back to your question:
Here is the signature of foldLeft (c...
how to create a file name with the current date & time in python?
... human readable.
from datetime import datetime
datetime.now().strftime("%Y_%m_%d-%I_%M_%S_%p")
'2020_08_12-03_29_22_AM'
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How to overcome TypeError: unhashable type: 'list'
...used to compare dictionary keys during a dictionary lookup quickly.
Internally, hash() method calls __hash__() method of an object which are set by default for any object.
Converting a nested list to a set
>>> a = [1,2,3,4,[5,6,7],8,9]
>>> set(a)
Traceback (most recent call last...
How do I setup a SSL certificate for an express.js server?
...
Other options for createServer are at: http://nodejs.org/api/tls.html#tls_tls_createserver_options_secureconnectionlistener
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How to create an object for a Django model with a many to many field?
...
For future visitors, you can create an object and all of its m2m objects in 2 queries using the new bulk_create in django 1.4. Note that this is only usable if you don't require any pre or post-processing on the data with save() methods or signals. What you insert is exactly...
Why does SIGPIPE exist?
...zero timeout) to consume any pending SIGPIPE signal (which is sent to the calling thread, not the process) before unmasking it again.
I believe the reason SIGPIPE exists is much simpler: establishing sane default behavior for pure "filter" programs that continuously read input, transform it somehow...
How do I show a Save As dialog in WPF?
...alog dialog = new SaveFileDialog()
{
Filter = "Text Files(*.txt)|*.txt|All(*.*)|*"
};
if (dialog.ShowDialog() == true)
{
File.WriteAllText(dialog.FileName, fileText);
}
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How do I use CSS in Django?
...igure out static files for the life of me. then, change django version installed, and voila. that was literally all i had to do because apparently i was looking at docs for the wrong version.
– Josh Brown
Sep 20 '13 at 3:56
...
Django - how to create a file and save it to a model's FileField?
...nt to have a look at FileField and FieldFile in the Django docs, and especially FieldFile.save().
Basically, a field declared as a FileField, when accessed, gives you an instance of class FieldFile, which gives you several methods to interact with the underlying file. So, what you need to do is:
s...