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Do declared properties require a corresponding instance variable?
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In your interface, you can formally declare an instance variable between the braces, or via @property outside the braces, or both. Either way, they become attributes of the class. The difference is that if you declare @property, then you can implement usin...
Scala: Nil vs List()
In Scala, is there any difference at all between Nil and List() ?
3 Answers
3
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How to get Scala List from Java List?
...now built into the language using:
import scala.collection.JavaConversions._
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lst.toList.foreach{ node => .... }
works. asScala did not work
In 2.12.x use import scala.collection.JavaConverters._
In 2.13.x use import scala.jdk.CollectionConverters._
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Deleting rows with MySQL LEFT JOIN
...ed May 4 '10 at 6:26
Daniel VassalloDaniel Vassallo
301k6666 gold badges475475 silver badges424424 bronze badges
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Why can't yield return appear inside a try block with a catch?
...ty. I suspect there are very, very few times where this restriction is actually an issue that can't be worked around - but the added complexity in the compiler would be very significant.
There are a few things like this that I've already encountered:
Attributes not being able to be generic
Inabil...
Is gcc std::unordered_map implementation slow? If so - why?
...2531
get : 1565
So std::unordered_map in gcc-4.7 is broken (or my installation, which is an installation of gcc-4.7.0 on Ubuntu - and another installation which is gcc 4.7.1 on debian testing).
I will submit a bug report.. until then: DO NOT use std::unordered_map with gcc 4.7!
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How can I use threading in Python?
...ticle/blog post that you should definitely check out (no affiliation) - Parallelism in one line: A Better Model for Day to Day Threading Tasks. I'll summarize below - it ends up being just a few lines of code:
from multiprocessing.dummy import Pool as ThreadPool
pool = ThreadPool(4)
results = pool.m...
How do I run a single test with Nose in Pylons
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nosetests appname.tests.functional.test_controller should work, where the file is named test_controller.py.
To run a specific test class and method use a path of the form module.path:ClassNameInFile.method_name, that is, with a colon separating the module/file pa...
SQLAlchemy: how to filter date field?
...In fact, your query is right except for the typo: your filter is excluding all records: you should change the <= for >= and vice versa:
qry = DBSession.query(User).filter(
and_(User.birthday <= '1988-01-17', User.birthday >= '1985-01-17'))
# or same:
qry = DBSession.query(User)....
MongoDB not equal to
...b.inventory.find( { price: { $not: { $gt: 1.99 } } } )
That would select all documents where:
The price field value is less than or equal to 1.99 or the price
Field does not exist
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