大约有 44,000 项符合查询结果（耗时：0.0637秒） [XML]
Django select only rows with duplicate field values
...ne these into a single query:
Literal.objects.filter(name__in=dups)
The extra call to .values('name') after the annotate call looks a little strange. Without this, the subquery fails. The extra values tricks the ORM into only selecting the name column for the subquery.
...
How to check whether a script is running under Node.js?
...bpack, process and process.version exists within the bundle, so I added an extra check for process.version where process.release.node is undefined on client side but has a node version as a value on server side
– Aaron
Feb 19 '17 at 1:49
...
What is the point of interfaces in PHP?
...can create. They define what methods a class must have, but you can create extra methods outside of those limitations.
I'm not sure what you mean by not being able to add code to methods - because you can. Are you applying the interface to an abstract class or the class that extends it?
A method ...
What's the difference between a Python “property” and “attribute”?
...
@martineau: Well, there's one extra function call, but most likely the extra work and time will depend on how much the property is doing (general advice: do /not/ use properties to hide I/O).
– Ethan Furman
Jun 25 '...
What are metaclasses in Python?
...ell, I guess it's a matter of consistency with str, the class that creates
strings objects, and int the class that creates integer objects. type is
just the class that creates class objects.
You see that by checking the __class__ attribute.
Everything, and I mean everything, is an object in Python. ...
How do you loop through each line in a text file using a windows batch file?
...ackq. Otherwise, the quotation marks are interpreted as defining a literal string to parse.
By the way, you can find the command-line help file on most Windows systems at:
"C:\WINDOWS\Help\ntcmds.chm"
share
|
...
How does Haskell printf work?
...t is in the types anyway.
class PrintfType r
printf :: PrintfType r => String -> r
So printf has an overloaded return type. In the trivial case, we have no extra arguments, so we need to be able to instantiate r to IO (). For this, we have the instance
instance PrintfType (IO ())
Next, i...
Webrick as production server vs. Thin or Unicorn?
...k, Sinatra, Rails, custom Webrick code, etc). This requires you to spin up extra ruby "handlers" to perform your rewrite code. For a low traffic site, this may be fine as you may have pre-warmed processes doing nothing already. However, for a higher traffic site, this is extra load on the server for...
Use of var keyword in C#
...e is
incredibly ugly because of all the
redundancy:
Dictionary<string, List<int>> mylists = new Dictionary<string, List<int>>();
And that's a simple example – I've
written worse. Any time you're forced
to type exactly the same thing twice,
that's a redun...
How do I tell git-svn about a remote branch created after I fetched the repo?
...
This will fetch ALL the remote branches that have not been fetched yet.
Extra tip: if you checked out only the trunk at first, and later you want to track ALL branches, then edit .git/config to look like this and re-run git svn fetch:
[svn-remote "svn"]
url = https://svn/path_to_repo_roo...