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Is there a performance difference between a for loop and a for-each loop?
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Yes, but that counter is now visible outside of the loop. Sure, it's a simple fix but so is for-each!
– Indolering
Nov 4 '12 at 5:19
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PowerShell script to return versions of .NET Framework on a machine?
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EDIT: For .Net 4.5 and up, this changed slightly again, so there's now a nice MSDN article here explaining how to convert the Release value to a .Net version number, it's a total train wreck :-(
This looks right to me (note that it outputs separate version numbers for WCF & WPF on 3.0. ...
Elegant way to invert a map in Scala
... different keys associated with same values. So, if you are interested in knowing all the keys, here's the code:
scala> val m = Map(1 -> "a", 2 -> "b", 4 -> "b")
scala> m.groupBy(_._2).mapValues(_.keys)
res0: Map[String,Iterable[Int]] = Map(b -> Set(2, 4), a -> Set(1))
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List goals/targets in GNU make that contain variables in their definition
...vial makefile, dummy.mk, with these contents:
__all_targets__: ; #no-op
Now invoke make as make -p -f Makefile -f dummy.mk __all_targets__. On any substantial build, the difference in the amount of output generated by make is significant. For example:
$ gmake -pn | wc
138985 2632330 69612711
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Why is __init__() always called after __new__()?
...it__ takes self as parameter. Until you create instance there is no self.
Now, I gather, that you're trying to implement singleton pattern in Python. There are a few ways to do that.
Also, as of Python 2.6, you can use class decorators.
def singleton(cls):
instances = {}
def getinstance(...
How do I pass JavaScript variables to PHP?
...current page PHP code... PHP code runs at the server side, and it doesn't know anything about what is going on on the client side.
You need to pass variables to PHP code from the HTML form using another mechanism, such as submitting the form using the GET or POST methods.
<DOCTYPE html>
<...
Do I need dependency injection in NodeJS, or how to deal with …?
... dbCon = require('./lib/mydbconnection'); //wherever the file is stored
//now do something with the connection
var connection = dbCon.fetchConnection(); //mydbconnection.js is responsible for pooling, reusing, whatever your app use case is
//come TEST time of SuperCoolWebApp, you can set the requi...
Remove by _id in MongoDB console
... new for the ObjectId.
Also, note that in some drivers/tools, remove() is now deprecated and deleteOne or deleteMany should be used instead.
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Compare object instances for equality by their attributes
...lemented
return self.foo == other.foo and self.bar == other.bar
Now it outputs:
>>> x == y
True
Note that implementing __eq__ will automatically make instances of your class unhashable, which means they can't be stored in sets and dicts. If you're not modelling an immutable ty...
Can scrapy be used to scrape dynamic content from websites that are using AJAX?
... a JSON file:
Which presents all the information I'm looking for.
From now, I must implement all this knowledge in scrapy. Let's define the spider for this purpose:
class spider(BaseSpider):
name = 'RubiGuesst'
start_urls = ['http://www.rubin-kazan.ru/guestbook.html']
def parse(sel...