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R object identification
... often ending up with a function producing output for which I don't understand the output data type. I'm expecting a list and it ends up being a list of lists or a data frame or something else. What's a good method or workflow for figuring out the output data type when first using a function?
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Recover unsaved SQL query scripts
...somebody stumbles into same problem.
Googled for Retrieve unsaved Scripts and found a solution.
Run the following select script. It provides a list of scripts and its time of execution in the last 24 hours. This will be helpful to retrieve the scripts, if we close our query window in SQL Server ma...
What does the “assert” keyword do? [duplicate]
...ed, execution of the assertion causes evaluation of the boolean expression and an error is reported if the expression evaluates to false. If the assertion is disabled, execution of the assertion has no effect whatsoever.
Where "enabled or disabled" is controlled with the -ea switch and "An error i...
Difference between local and global indexes in DynamoDB
I'm curious about these two secondary indexes and differences between them. It is hard to imagine how this looks like. And I think, this will help more people than just me.
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When is it better to use an NSSet over an NSArray?
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In your example, you are adding primitives to an array and a set. Neither is possible because they can only contain objects.
– FreeAsInBeer
Jun 12 '12 at 13:28
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Does JSON syntax allow duplicate keys in an object?
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From the standard (p. ii):
It is expected that other standards will refer to this one, strictly adhering to the JSON text format, while
imposing restrictions on various encoding details. Such standards may require specific behavi...
Select every Nth element in CSS
...ddition to constant numbers. You can perform addition (+), subtraction (-) and coefficient multiplication (an where a is an integer, including positive numbers, negative numbers and zero).
Here's how you would rewrite the above selector list:
div:nth-child(4n)
For an explanation on how these ari...
Compare two files in Visual Studio
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You can invoke devenv.exe /diff list1.txt list2.txt from the command prompt or, if a Visual Studio instance is already running, you can type Tools.DiffFiles in the Command window, with a handy file name completion:
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How to escape indicator characters (i.e. : or - ) in YAML
...ey to which I wish to assign a URL. The problem is that YAML interprets : and - characters as either creating mappings or lists, so it has a problem with the line
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Removing duplicates from a list of lists
...pby(k))
[[1, 2], [3], [4], [5, 6, 2]]
itertools often offers the fastest and most powerful solutions to this kind of problems, and is well worth getting intimately familiar with!-)
Edit: as I mention in a comment, normal optimization efforts are focused on large inputs (the big-O approach) becaus...