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Best implementation for hashCode method for a collection
...ins there why the approach is good.
A short version
Create a int result and assign a non-zero value.
For every field f tested in the equals() method, calculate a hash code c by:
If the field f is a boolean:
calculate (f ? 0 : 1);
If the field f is a byte, char, short or int: calculate (int)f;
...
Passing base64 encoded strings in URL
...would need to url-encode it, since base64 strings can contain the "+", "=" and "/" characters which could alter the meaning of your data - look like a sub-folder.
Valid base64 characters are below.
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=
...
No appenders could be found for logger(log4j)?
...valid.
That guide will give you some information about how to use loggers and appenders.
Just to get you going you have two simple approaches you can take.
First one is to just add this line to your main method:
BasicConfigurator.configure();
Second approach is to add this standard log4j.pro...
RuntimeWarning: invalid value encountered in divide
...is trying to "divide by zero" or "divide by NaN". If you are aware of that and don't want it to bother you, then you can try:
import numpy as np
np.seterr(divide='ignore', invalid='ignore')
For more details see:
http://docs.scipy.org/doc/numpy/reference/generated/numpy.seterr.html
...
Something like 'contains any' for Java set?
I have two sets, A and B, of the same type.
9 Answers
9
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How to match “anything up until this sequence of characters” in a regular expression?
...s possible to satisfy.
When using .+?, instead of matching all at once and going back for
other conditions (if any), the engine will match the next characters by
step until the subsequent part of the regex is matched (again if any).
This is the un-greedy, meaning match the fewest possi...
How to check a checkbox in capybara?
I'm using Rspec and Capybara.
13 Answers
13
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The way to check a HDFS directory's size?
...
Prior to 0.20.203, and officially deprecated in 2.6.0:
hadoop fs -dus [directory]
Since 0.20.203 (dead link) 1.0.4 and still compatible through 2.6.0:
hdfs dfs -du [-s] [-h] URI [URI …]
You can also run hadoop fs -help for more info and...
Reading a binary file with python
...particularly difficult reading binary file with Python. Can you give me a hand?
I need to read this file, which in Fortran 90 is easily read by
...
Clean ways to write multiple 'for' loops
.../ ...
}
(or just:
for ( auto& elem: m ) {
}
if you have C++11.)
And if you need the three indexes during such iterations, it's
possible to create an iterator which exposes them:
class Matrix3D
{
// ...
class iterator : private std::vector<int>::iterator
{
Matri...