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Why doesn't a python dict.update() return the object?
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Python's mostly implementing a pragmatically tinged flavor of command-query separation: mutators return None (with pragmatically induced exceptions such as pop;-) so they can't possibly be confused with accessors (and in the same vein, assignment is not an expressi...
Replace whole line containing a string using Sed
...cusDowning GNU sed does not require the space; it works just fine as originally posted. If your particular sed requires the space, then by all means note which sed is incompatible and add the necessary invocation as a comment. However, please don't change working code in an accepted answer.
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Django: Get an object form the DB, or 'None' if nothing matches
...get(*args, **kwargs)
except model.DoesNotExist:
return None
Call it like this
foo = get_or_none(Foo, baz=bar)
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Can I call a constructor from another constructor (do constructor chaining) in C++?
...legating constructors).
The syntax is slightly different from C#:
class Foo {
public:
Foo(char x, int y) {}
Foo(int y) : Foo('a', y) {}
};
C++03: No
Unfortunately, there's no way to do this in C++03, but there are two ways of simulating this:
You can combine two (or more) constructors v...
What does $@ mean in a shell script?
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$@ is all of the parameters passed to the script.
For instance, if you call ./someScript.sh foo bar then $@ will be equal to foo bar.
If you do:
./someScript.sh foo bar
and then inside someScript.sh reference:
umbrella_corp_...
What's the @ in front of a string in C#?
...tring as a verbatim string literal - anything in the string that would normally be interpreted as an escape sequence is ignored.
So "C:\\Users\\Rich" is the same as @"C:\Users\Rich"
There is one exception: an escape sequence is needed for the double quote. To escape a double quote, you need to put...
How do I find a stored procedure containing ?
... A million times what @PeteT said. This 4000 character limit really bit me a few years ago.
– Vivian River
Mar 31 '15 at 17:40
16
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How can I beautify JavaScript code using Command Line?
...y-web/js-beautify/blob/master/js/lib/beautify.js
Second, download and install The Mozilla group's Java based Javascript engine, Rhino. "Install" is a little bit misleading; Download the zip file, extract everything, place js.jar in your Java classpath (or Library/Java/Extensions on OS X). You ca...
How to create file execute mode permissions in Git on Windows?
... would be nice if git-add had a --mode flag
git 2.9.x/2.10 (Q3 2016) actually will allow that (thanks to Edward Thomson):
git add --chmod=+x -- afile
git commit -m"Executable!"
That makes the all process quicker, and works even if core.filemode is set to false.
See commit 4e55ed3 (31 May 2016)...
Download data url file
... just drag their zip directly into the browser and it'll let them download all the files within. They can also create new zip files by dragging individual files in.
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