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Why shouldn't I use PyPy over CPython if PyPy is 6.3 times faster?
...to mention, has tenuous support for C extensions. It has support, but typically at slower-than-Python speeds and it's iffy at best. Hence a lot of modules simply require CPython. PyPy doesn't support numpy PyPy now supports numpy. Some extensions are still not supported (Pandas, SciPy, etc.), take a...
What's the difference between VARCHAR and CHAR?
...your content is a fixed size" it means the rows of your table must contain all fixed size fields. You get no performance improvement if you use CHAR against VARCHAR in one field, but the table contains other fields that are VARCHAR.
– Marco Demaio
May 20 '10 at...
How do I “Add Existing Item” an entire directory structure in Visual Studio?
I have a free standing set of files not affiliated with any C# project at all that reside in a complicated nested directory structure.
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java: (String[])List.toArray() gives ClassCastException
...hat type of array to create.
use
toArray(new String[v2.size()]);
which allocates the right kind of array (String[] and of the right size)
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Call a stored procedure with parameter in c#
...do a delete, insert and update in my program and I try to do an insert by call a created stored procedure from my database.
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How to calculate “time ago” in Java?
In Ruby on Rails, there is a feature that allows you to take any Date and print out how "long ago" it was.
30 Answers
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Using ls to list directories and their total sizes
...possible to use ls in Unix to list the total size of a sub-directory and all its contents as opposed to the usual 4K that (I assume) is just the directory file itself?
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Check number of arguments passed to a Bash script
...nd regex matching.
The following example checks if arguments are valid. It allows a single argument or two.
[[ ($# -eq 1 || ($# -eq 2 && $2 == <glob pattern>)) && $1 =~ <regex pattern> ]]
For pure arithmetic expressions, using (( )) to some may still be better, but they ...
Integer to hex string in C++
...(sizeof(your_type)*2)
<< std::hex << your_int;
So finally, I'd suggest such a function:
template< typename T >
std::string int_to_hex( T i )
{
std::stringstream stream;
stream << "0x"
<< std::setfill ('0') << std::setw(sizeof(T)*2)
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Parsing CSV files in C#, with header
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Let a library handle all the nitty-gritty details for you! :-)
Check out FileHelpers and stay DRY - Don't Repeat Yourself - no need to re-invent the wheel a gazillionth time....
You basically just need to define that shape of your data - the fi...