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Fastest way to determine if record exists
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@Declan_K: seems like my magic sphere failed in this case and a column entitled as id isn't PK. So +1 to your advice.
– zerkms
Aug 7 '13 at 22:00
4
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passing several arguments to FUN of lapply (and others *apply)
...n the lapply call as an argument, like so:
lapply(input, myfun, arg1=6)
and lapply, recognizing that arg1 is not an argument it knows what to do with, will automatically pass it on to myfun. All the other apply functions can do the same thing.
An addendum: You can use ... when you're writing you...
source of historical stock data [closed]
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Let me add my 2¢, it's my job to get good and clean data for a hedge-fund, I've seen quite a lot of data feeds and historical data providers. This is mainly about US stock data.
To start with, if you have some money don't bother with downloading data from Yahoo, get...
Sublime text 2 - find and replace globally ( all files and in all directories )
Is there any way to find and replace text string automatically in all folder's files ?
2 Answers
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How to track down a “double free or corruption” error
...You can set this from gdb by using the set environment MALLOC_CHECK_ 2 command before running your program; the program should abort, with the free() call visible in the backtrace.
see the man page for malloc() for more information
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How do you split and unsplit a window/view in Eclipse IDE?
...or splitting is:
Azerty keyboard:
Ctrl + _ for split horizontally, and
Ctrl + { for split vertically.
Qwerty US keyboard:
Ctrl + Shift + - (accessing _) for split horizontally, and
Ctrl + Shift + [ (accessing {) for split vertically.
MacOS - Qwerty US keyboard:
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What does 'synchronized' mean?
I have some questions regarding the usage and significance of the synchronized keyword.
17 Answers
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C# Object Pooling Pattern implementation
... the base class library (BCL). You can read the original GitHub issue here and view the code for System.Buffers. Currently the ArrayPool is the only type available and is used to pool arrays. There is a nice blog post here.
namespace System.Buffers
{
public abstract class ArrayPool<T>
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How do I create a list of random numbers without duplicates?
I tried using random.randint(0, 100) , but some numbers were the same. Is there a method/module to create a list unique random numbers?
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Items in JSON object are out of order using “json.dumps”?
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Both Python dict (before Python 3.7) and JSON object are unordered collections. You could pass sort_keys parameter, to sort the keys:
>>> import json
>>> json.dumps({'a': 1, 'b': 2})
'{"b": 2, "a": 1}'
>>> json.dumps({'a': 1, 'b': 2},...