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JSON: why are forward slashes escaped?
... JSON in a <script> tag, which doesn't allow </ inside strings, like Seb points out.
Some of Microsoft's ASP.NET Ajax/JSON API's use this loophole to add extra information, e.g., a datetime will be sent as "\/Date(milliseconds)\/". (Yuck)
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How to empty a list?
...example:
lst1 = [1, 2, 3]
lst2 = lst1
del lst1[:]
print(lst2)
For the sake of completeness, the slice assignment has the same effect:
lst[:] = []
It can also be used to shrink a part of the list while replacing a part at the same time (but that is out of the scope of the question).
Note that ...
Test whether a list contains a specific value in Clojure
...ains?... supposedly one of the top five FAQs re: Clojure.
It does not check whether a collection contains a value; it checks whether an item could be retrieved with get or, in other words, whether a collection contains a key. This makes sense for sets (which can be thought of as making no distincti...
'POCO' definition
...her answers have stated, it is technically "Plain Old CLR Object" but I, like David Arno comments, prefer "Plain Old Class Object" to avoid ties to specific languages or technologies.
TO CLARIFY: In other words, they don’t derive from
some special base class, nor do they return any special type...
Copy object values in Visual Studio debug mode
...'s possible to hover over variables to show their value and then right-click to "Copy", "Copy Expression" or "Copy Value".
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How to print last two columns using awk
...
You can make use of variable NF which is set to the total number of fields in the input record:
awk '{print $(NF-1),"\t",$NF}' file
this assumes that you have at least 2 fields.
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Remove NA values from a vector
...cluding sum(), mean(), etc.)
Setting na.rm=TRUE does just what you're asking for:
d <- c(1, 100, NA, 10)
max(d, na.rm=TRUE)
If you do want to remove all of the NAs, use this idiom instead:
d <- d[!is.na(d)]
A final note: Other functions (e.g. table(), lm(), and sort()) have NA-related...
Programmatically trigger “select file” dialog box
...Is it possible to trigger its select file dialog box from a button's click event?
13 Answers
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How to compute the sum and average of elements in an array?
...d Apr 28 '12 at 1:54
Marcus RecckMarcus Recck
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Detect if stdin is a terminal or pipe?
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RichieHindleRichieHindle
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