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Are tuples more efficient than lists in Python?
...efficient.
This gives tuples a nice space advantage:
>>> import sys
>>> sys.getsizeof(tuple(iter(range(10))))
128
>>> sys.getsizeof(list(iter(range(10))))
200
Here is the comment from Objects/listobject.c that explains what lists are doing:
/* This over-allocates prop...
Iterator Loop vs index loop [duplicate]
.... If your container's size is larger than INT_MAX then obviously you can't convert it to int and the code fails. long long would be safer (especially as it's finally standard). I will never create a vector with 2^63 elements but I might with 2^31.
– Steve Jessop
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SQL command to display history of queries
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cat ~/.mysql_history
this will show you all mysql commands ran on the system
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How to check if any flags of a flag combination are set?
...T : struct
{
CheckIsEnum<T>(true);
long lValue = Convert.ToInt64(value);
long lFlag = Convert.ToInt64(flag);
return (lValue & lFlag) != 0;
}
public static IEnumerable<T> GetFlags<T>(this T value) where T : struct
{
CheckI...
Generate a random number in the range 1 - 10
...: select (trunc(random() * 10) % 10) + 1
The output from trunc has to be converted to INTEGER. But it can be done without trunc. So it turns out to be simple.
select (random() * 9)::INTEGER + 1
Generates an INTEGER output in range [1, 10] i.e. both 1 & 10 inclusive.
For any number (floats)...
How do I list all the columns in a table?
For the various popular database systems, how do you list all the columns in a table?
12 Answers
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How can I return NULL from a generic method in C#?
... the problem with this is that if you're using this generic method to say, convert a Database object from DbNull to Int and it returns default(T) where T is an int, it'll return 0. If this number is actually meaningful, then you'd be passing around bad data in cases where that field was null. Or a b...
How to resize an Image C#
...< nPercentW)
{
nPercent = nPercentH;
destX = System.Convert.ToInt16((newWidth -
(sourceWidth * nPercent)) / 2);
}
else
{
nPercent = nPercentW;
destY = System.Convert.ToInt16((newHeight -
(sourceHeight * nPercent))...
How to include (source) R script in other scripts
...e, checks to see if the file has been loaded into the environment and uses sys.source to source the file if not.
Here's a quick and untested function (improvements welcome!):
include <- function(file, env) {
# ensure file and env are provided
if(missing(file) || missing(env))
stop("'fil...
Difference between declaring variables before or in loop?
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So both look exactly same after compilation. In managed languages code is converted into CL/byte code and at time of execution it's converted into machine language. So in machine language a double may not even be created on the stack. It may just be a register as code reflect that it is a temporary...