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SQL Server indexes - ascending or descending, what difference does it make?
...ces to rows.
Since the table is clustered, the references to rows are actually the values of the pk. They are also ordered within each value of col1.
This means that that leaves of the index are actually ordered on (col1, pk), and this query:
SELECT col1, pk
FROM mytable
ORDER BY
col1...
What column type/length should I use for storing a Bcrypt hashed password in a Database?
... I don't get the reason why I should bother about binary or not binary at all, if I don't want to sort by password hash, compare hashes on database layer or make the password column unique (“Sorry, this password is already in use”) at all. I'd recommend using UTF8 everywhere. In that case there...
check if variable is dataframe
...rame
Yes: isinstance(x, pd.DataFrame)
And don't even think about
if obj.__class__.__name__ = 'DataFrame':
expect_problems_some_day()
isinstance handles inheritance (see What are the differences between type() and isinstance()?). For example, it will tell you if a variable is a string (eithe...
How to check if object (variable) is defined in R?
...
heh. Happens to me all the time when I am testing out examples before posting, Gavin or Josh have already answered it.
– Maiasaura
Feb 20 '12 at 22:17
...
What Every Programmer Should Know About Memory?
....
So, any book or article that describes something fundamental cannot be called outdated. "What every programmer should know about memory" is definitely worth to read, but, well, I don't think it's for "every programmer". It's more suitable for system/embedded/kernel guys.
...
Get selected subcommand with argparse
...s:
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('-g', '--global')
>>> subparsers = parser.add_subparsers(dest="subparser_name") # this line changed
>>> foo_parser = subparsers.add_parser('foo')
>>> foo_parser.add_argument('-c', '--count...
How do you know when to use fold-left and when to use fold-right?
...ee it. It's "haskell-style pseudocode". :)
– laughing_man
Apr 21 '15 at 2:38
...
Python Threading String Arguments
...t list
processThread.start()
If you notice, from the stack trace: self.__target(*self.__args, **self.__kwargs)
The *self.__args turns your string into a list of characters, passing them to the processLine
function. If you pass it a one element list, it will pass that element as the first argum...
instantiate a class from a variable in PHP?
...you work with namespace, put the current namespace into the string: $var = __NAMESPACE__ . '\\' . $var . 'Class';
– bastey
Sep 2 '13 at 13:28
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Why can I initialize a List like an array in C#?
... has a method named Add(...)
What happens is the default constructor is called, and then Add(...) is called for each member of the initializer.
Thus, these two blocks are roughly identical:
List<int> a = new List<int> { 1, 2, 3 };
And
List<int> temp = new List<int>();
...