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data.table vs dplyr: can one do something well the other can't or does poorly?
... the moment allows one to modify/update columns by reference (note that we don't need to re-assign the result back to a variable).
# sub-assign by reference, updates 'y' in-place
DT[x >= 1L, y := NA]
But dplyr will never update by reference. The dplyr equivalent would be (note that the result ...
TypeScript: casting HTMLElement
Does anyone know how to cast in TypeScript?
13 Answers
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How do I get the day of the week with Foundation?
How do I get the day of the week as a string?
13 Answers
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When saving, how can you check if a field has changed?
... so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharField()
__original_name = None
def __init__(self, *args, **kwargs):
super(Person, self)._...
Do I set properties to nil in dealloc when using ARC?
...
Short answer: no, you do not have to nil out properties in dealloc under ARC.
Long answer: You should never nil out properties in dealloc, even in manual memory management.
In MRR, you should release your ivars. Nilling out properties means call...
How do you organize your version control repository?
..., as long as you preserve the structure from the project root directory on down
-- build each project anywhere on any machine, with minimum risk and minimum preparation
-- build each project completely stand-alone, as long as you have access to its binary dependencies (local "library" and "output"...
Why do we need fibers
...seful
# enum_for is an Object method
# so even for iterators which don't return an Enumerator when called
# with no block, you can easily get one by calling 'enum_for'
return enum_for(:an_iterator) if not block_given?
yield 1
yield 2
yield 3
end
end
Let's try it:
e...
SQLite: How do I save the result of a query as a CSV file?
...e> .output test.csv
sqlite> select * from tbl1;
sqlite> .output stdout
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How do I make Git ignore file mode (chmod) changes?
... via CIFS mount, visiting a Cygwin created repository with Git
for Windows or Eclipse). In such a case it may be necessary
to set this variable to false. See git-update-index(1).
The default is true (when core.filemode is not specified
in the config file).
The -c flag can be use...
Unicode Processing in C++
...
If you don't care about backwards compatibility with previous C++ standards, the current C++11 standard has built in Unicode support: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2011/n3242.pdf
So the truly best practice for ...