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Converting an array of objects to ActiveRecord::Relation
...al data.
However, if what you want is a relation then:
for ActiveRecord 3.x, don’t call all and instead call scoped, which will give back a Relation which represents the same records that all would give you in an Array.
for ActiveRecord 4.x, simply call all, which returns a Relation.
When ...
How to keep Maven profiles which are activeByDefault active even if another profile gets activated?
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Kariem
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answered Sep 20 '11 at 7:07
seanfseanf
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What is this CSS selector? [class*=“span”]
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336
It's an attribute wildcard selector. In the sample you've given, it looks for any child elemen...
Creating a new column based on if-elif-else condition
...df['C'] = df.apply(f, axis=1)
In [2]: df
Out[2]:
A B C
a 2 2 0
b 3 1 1
c 1 3 -1
Of course, this is not vectorized so performance may not be as good when scaled to a large number of records. Still, I think it is much more readable. Especially coming from a SAS background.
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What's a standard way to do a no-op in python?
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edited Dec 18 '09 at 3:41
answered Mar 27 '09 at 17:05
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Is an array name a pointer?
..., and you can put a value in one of them with an assignment, like this:
a[3] = 9;
Here is a pointer:
int *p;
p doesn't contain any spaces for integers, but it can point to a space for an integer. We can, for example, set it to point to one of the places in the array a, such as the first one:
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How to hide databases that I am not allowed to access
When I connect to my Heroku - Postgresql database via pgAdmin3 , It lists all the tables (about 2600). Every time I open the pgAdmin3 I have to find my own database.
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Formatting numbers (decimal places, thousands separators, etc) with CSS
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answered Oct 9 '18 at 21:32
CascadiaJSCascadiaJS
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multiprocessing: sharing a large read-only object between processes?
...ocessing share objects created earlier in the program?"
No (python before 3.8), and Yes in 3.8 (https://docs.python.org/3/library/multiprocessing.shared_memory.html#module-multiprocessing.shared_memory)
Processes have independent memory space.
Solution 1
To make best use of a large structure wit...
Why does this code using random strings print “hello world”?
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answered Mar 3 '13 at 4:40
FThompsonFThompson
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