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Grouped LIMIT in PostgreSQL: show the first N rows for each group?
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For those who works with like millions rows and seeks for really performant way to do this - poshest's answer is the way to go. Just dont forget to spice ti up with proper indexing.
– Diligent Key Presser
Jun 20 '19 at 8:46
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super() fails with error: TypeError “argument 1 must be type, not classobj” when parent does not inh
...t declared as a "new-style" class. Change it like so:
class B(object):
and it will work.
super() and all subclass/superclass stuff only works with new-style classes. I recommend you get in the habit of always typing that (object) on any class definition to make sure it is a new-style class.
O...
Difference between private, public, and protected inheritance
...g "next:".
There are three accessors that I'm aware of: public, protected and private.
Let:
class Base {
public:
int publicMember;
protected:
int protectedMember;
private:
int privateMember;
};
Everything that is aware of Base is also aware that Base contai...
Why can't C++ be parsed with a LR(1) parser?
I was reading about parsers and parser generators and found this statement in wikipedia's LR parsing -page:
6 Answers
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What does .SD stand for in data.table in R
...ks useful but I do not really know what I am doing with it. What does it stand for? Why is there a preceding period (full stop). What is happening when I use it?
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JavaScript exponents
...inal specification. It is supposed to work in a similar manner with python and matlab:
a**b // will rise a to the power b
Now it is already implemented in Edge14, Chrome52, and also it is available with traceur or babel.
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How can I find a specific element in a List?
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Note: C# has a built-in syntax for properties. Instead of writing getter and setter methods (as you might be used to from Java), write
private string _id;
public string Id
{
get
{
return _id;
}
set
{
_id = value;
}
}
value is a contextual keyword known on...
How do I select a merge strategy for a git rebase?
...xtra options that are understood by the chosen merge strategy.
NB: "Ours" and "theirs" mean the opposite of what they do during a straight merge. In other words, "theirs" favors the commits on the current branch.
share
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In Python, how do I create a string of n characters in one line of code?
...e same letter 10 times:
string_val = "x" * 10 # gives you "xxxxxxxxxx"
And if you want something more complex, like n random lowercase letters, it's still only one line of code (not counting the import statements and defining n):
from random import choice
from string import ascii_lowercase
n = ...
How to change Git log date formats
...g "--pretty". log.date config variable
sets a default value for log command’s --date option.
--date=relative shows dates relative to the current time, e.g. "2 hours ago".
--date=local shows timestamps in user’s local timezone.
--date=iso (or --date=iso8601) shows timestamps in ISO 8601 for...