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Hadoop “Unable to load native-hadoop library for your platform” warning
...e native Hadoop library $HADOOP_HOME/lib/native/libhadoop.so.1.0.0 was actually compiled on 32 bit.
Anyway, it's just a warning, and won't impact Hadoop's functionalities.
Here is the way if you do want to eliminate this warning, download the source code of Hadoop and recompile libhadoop.so.1.0....
Better way to check variable for null or empty string?
...solves it, I'm not sure if it's simpler. +1 anyway
– Allain Lalonde
Dec 19 '08 at 15:36
4
Since O...
Extending an Object in Javascript
... I have one question: how is the Person() constructor being called when you do new Robot()? It seems to me that you should call that base class constructor instead of doing this.name = name; in the Robot() constructor...
– Alexis Wilke
Apr 7 '14 a...
Auto reloading python Flask app upon code changes
...nt recommended way is with the flask command line utility.
https://flask.palletsprojects.com/en/1.1.x/quickstart/#debug-mode
Example:
$ export FLASK_APP=main.py
$ export FLASK_ENV=development
$ flask run
or in one command:
$ FLASK_APP=main.py FLASK_ENV=development flask run
If you want diff...
Convert hex string to int in Python
... 16)
With the 0x prefix, Python can distinguish hex and decimal automatically.
>>> print int("0xdeadbeef", 0)
3735928559
>>> print int("10", 0)
10
(You must specify 0 as the base in order to invoke this prefix-guessing behavior; omitting the second parameter means to assume ba...
Case objects vs Enumerations in Scala
... deal with an Option[Currency] type that would clearly indicate there is really a matching problem and "encourage" the user of the API to sort it out him/herself.
To follow up on the other answers here, the main drawbacks of case objects over Enumerations are:
Can't iterate over all instances of t...
Select random lines from a file
... @MonaJalal nope just faster, since it doesn't have to compare lines at all.
– rogerdpack
May 15 '17 at 17:20
Does ...
How does Dijkstra's Algorithm and A-Star compare?
...t; but it is a special case of the more general algorithm A*. It is not at all unusual (in fact, probably the norm) for special cases to be discovered first, and then subsequently be generalized .
– Pieter Geerkens
Sep 2 '13 at 15:37
...
What does O(log n) mean exactly?
...g that the size of the input affects the growth of the algorithm proportionally...and the same goes for, for example, quadratic time O(n2) etc..even algorithms, such as permutation generators, with O(n!) times, that grow by factorials.
...
Generating random numbers in Objective-C
...te the S-Boxes via
arc4random_addrandom().
There is no need to call arc4random_stir() before using arc4random(), since arc4random() automatically
initializes itself.
EXAMPLES
The following produces a drop-in replacement for the traditional rand() and random() functions using
...