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Django select only rows with duplicate field values
... syntax is also how Django interprets you wanting to do a join. So, essentially when you try to filter on that, Django thinks you're trying to do a join with count which obviously doesn't exist. The fix is to specify a name for your annotation result, i.e. annotate(mycount=Count('id')) and then filt...
Does use of final keyword in Java improve the performance?
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Usually not. For virtual methods, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn't been overridden - until it lo...
Chrome Extension how to send data from content script to popup.html
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Although you are definitely in the right direction (and actually pretty close to the end), there are several (imo) bad practises in your code (e.g. injecting a whole library (jquery) for such a trivial task, declaring unnecessary permissions, making superflous calls to API methods etc...
Why does this go into an infinite loop?
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Note: Originally I posted C# code in this answer for purposes of illustration, since C# allows you to pass int parameters by reference with the ref keyword. I've decided to update it with actual legal Java code using the first MutableInt...
What is the smallest possible valid PDF?
Out of simple curiosity, having seen the smallest GIF , what is the smallest possible valid PDF file?
4 Answers
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'id' is a bad variable name in Python
... keyword or built-in function in any language is a bad idea, even if it is allowed.
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How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
Mercurial .hgignore for Visual Studio 2008 projects
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Here's my standard .hgignore file for use with VS2008 that was originally modified from a Git ignore file:
# Ignore file for Visual Studio 2008
# use glob syntax
syntax: glob
# Ignore Visual Studio 2008 files
*.obj
*.exe
*.pdb
*.user
*.aps
*.pch
*.vspscc
*_i.c
*_p.c
*.ncb
*.suo
*.tlb
*.tlh
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svn : how to create a branch from certain revision of trunk
...tart of the date
'HEAD' latest in repository
'BASE' base rev of item's working copy
'COMMITTED' last commit at or before BASE
'PREV' revision just before...
How to get URL of current page in PHP [duplicate]
...e - the former has the path to the actual script, the latter has the originally requested path.
– Amber
Aug 16 '09 at 2:19
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