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Name node is in safe mode. Not able to leave
...e leave
hadoop dfsadmin has been deprecated and so is hadoop fs command, all hdfs related tasks are being moved to a separate command hdfs.
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What is your preferred style for naming variables in R? [closed]
...
Good previous answers so just a little to add here:
underscores are really annoying for ESS users; given that ESS is pretty widely used you won't see many underscores in code authored by ESS users (and that set includes a bunch of R Core as well as CRAN authors, excptions like Hadley notwithsta...
ASP.NET MVC: What is the purpose of @section? [closed]
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@section is for defining a content are override from a shared view. Basically, it is a way for you to adjust your shared view (similar to a Master Page in Web Forms).
You might find Scott Gu's write up on this very interesting.
Edit: Based on additional question clarification
The @RenderSection...
How to convert ActiveRecord results into an array of hashes
...d objects to Ruby Hashes despite its name
tasks_records = TaskStoreStatus.all
tasks_records = tasks_records.as_json
# You can now add new records and return the result as json by calling `to_json`
tasks_records << TaskStoreStatus.last.as_json
tasks_records << { :task_id => 10, :sto...
Difference between single and double square brackets in Bash
...nt of [ that prevents further arguments from being used.
Ubuntu 16.04 actually has an executable for it at /usr/bin/[ provided by coreutils, but the bash built-in version takes precedence.
Nothing is altered in the way that Bash parses the command.
In particular, < is redirection, && a...
Safely turning a JSON string into an object
...here's how you do it in Prototype (JSON tutorial).
new Ajax.Request('/some_url', {
method:'get',
requestHeaders: {Accept: 'application/json'},
onSuccess: function(transport){
var json = transport.responseText.evalJSON(true);
}
});
Calling evalJSON() with true as the argument sanitizes...
How to delete or add column in SQLITE?
...upports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table.
You can:
create new table as the one you ar...
Request is not available in this context
...on here: stackoverflow.com/questions/1790457/…
– jball
Mar 25 '10 at 17:55
6
Thanks. I had seen...
Omitting the second expression when using the if-else shorthand
...o an option:
x==2 && dosomething();
dosomething() will only be called if x==2 is evaluated to true. This is called Short-circuiting.
It is not commonly used in cases like this and you really shouldn't write code like this. I encourage this simpler approach:
if(x==2) dosomething();
You...
Why do I need 'b' to encode a string with Base64?
...-z, 0-9, +, /* so it can be transmitted over channels that do not preserve all 8-bits of data, such as email.
Hence, it wants a string of 8-bit bytes. You create those in Python 3 with the b'' syntax.
If you remove the b, it becomes a string. A string is a sequence of Unicode characters. base64 ha...