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Apache Spark: map vs mapPartitions?
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I'm seeing the opposite -- even with very small operations, its faster to call mapPartitions and iterate than call map. I am assuming that this is just the overhead of starting the language engine that will process the map task. (I'm in R, which may have more startup...
How do I get the last inserted ID of a MySQL table in PHP?
...ng PDO, use PDO::lastInsertId.
If you're using Mysqli, use mysqli::$insert_id.
If you're still using Mysql:
Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO or MyS...
Setting environment variables for accessing in PHP when using Apache
I have a Linux environment and I have a PHP Web Application that conditionally runs based on environment variables using getenv in PHP. I need to know how these environment variables need to be set for the application to work correctly. I am not sure how to set this up on Apache.
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How to explicitly discard an out argument?
...ublic void PrintXCoordinate(Point p)
{
p.GetCoordinates(out int x, out _); // I only care about x
WriteLine($"{x}");
}
Source: https://blogs.msdn.microsoft.com/dotnet/2017/03/09/new-features-in-c-7-0/
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How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?
...cessary instead of DateTime. So use Time.strptime("1318996912345",'%Q').to_f and you will see the milliseconds preserved, while DateTime.strptime("1318996912345",'%Q').to_f does not preserve it.
– skensell
Feb 22 '17 at 15:20
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Regular Expression to match only alphabetic characters
...z]+$/
to match an input string of ASCII alphabets.
[A-Za-z] will match all the alphabets (both lowercase and uppercase).
^ and $ will make sure that nothing but these alphabets will be matched.
Code:
preg_match('/^[A-Z]+$/i', "abcAbc^Xyz", $m);
var_dump($m);
Output:
array(0) {
}
Test cas...
Replacing all non-alphanumeric characters with empty strings
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Use [^A-Za-z0-9].
Note: removed the space since that is not typically considered alphanumeric.
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Changes in import statement python3
...a single function. In Python 2 you were permitted to be semi-lazy:
def sin_degrees(x):
from math import *
return sin(degrees(x))
Note that it already triggers a warning in Python 2:
a.py:1: SyntaxWarning: import * only allowed at module level
def sin_degrees(x):
In modern Python 2 co...
Nullable Foreign Key bad practice?
... read.
Only if you know better than Chris Date "what first normal form really means". If x and y are both nullable, and indeed in some row x and y are both null, then WHERE x=y does not yield true. This proves beyond reasonable doubt that null is not a value (because any real value is always equ...
Save bitmap to location
...my image in canvas it is very small. any reason?
– AZ_
Mar 18 '11 at 13:24
3
@Aizaz This will not...