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Difference between len() and .__len__()?
...y calling an object's __len__ method. __something__ attributes are special and usually more than meets the eye, and generally should not be called directly.
It was decided at some point long ago getting the length of something should be a function and not a method code, reasoning that len(a)'s mean...
The difference between try/catch/throw and try/catch(e)/throw e
...milar in that both will catch every exception thrown inside the try block (and, unless you are simply using this to log the exceptions, should be avoided). Now look at these:
try { ... }
catch ()
{
/* ... */
throw;
}
try { ... }
catch (Exception e)
{
/* ... */
throw;
}
try { ... }...
How do I convert a String to an InputStream in Java?
...s:
InputStream stream = new ByteArrayInputStream(exampleString.getBytes(StandardCharsets.UTF_8));
Note that this assumes that you want an InputStream that is a stream of bytes that represent your original string encoded as UTF-8.
For versions of Java less than 7, replace StandardCharsets.UTF_8 w...
Shorthand way for assigning a single field in a record, while copying the rest of the fields?
...
And lenses-like packages often define operators in addition to functions for getting and setting fields. For example, test $ c .~ "Goodbye" is how lens would do it iirc. I'm not saying this is intutitive, but once you know ...
What's the difference between == and .equals in Scala?
What is the difference between == and .equals() in Scala, and when to use which?
5 Answers
...
Select rows of a matrix that meet a condition
...matrix(1:20, ncol = 4)
colnames(m) <- letters[1:4]
The following command will select the first row of the matrix above.
subset(m, m[,4] == 16)
And this will select the last three.
subset(m, m[,4] > 17)
The result will be a matrix in both cases.
If you want to use column names to selec...
Why does Java's Arrays.sort method use two different sorting algorithms for different types?
Java 6's Arrays.sort method uses Quicksort for arrays of primitives and merge sort for arrays of objects. I believe that most of time Quicksort is faster than merge sort and costs less memory. My experiments support that, although both algorithms are O(n log(n)). So why are different algorithms us...
How do I find if a string starts with another string in Ruby?
...ingly, Rails defines the grammaticaly correct starts_with?, which in 1.8.7 and above is just aliased to start_with?.
– Mark Thomas
Nov 13 '10 at 14:57
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How to submit a form using PhantomJS
... tool btw!) to submit a form for a page that I have login credentials for, and then output the content of the destination page to stdout. I'm able to access the form and set its values successfully using phantom, but I'm not quite sure what the right syntax is to submit the form and output the conte...
Is a Python dictionary an example of a hash table?
...read more about hash tables or check how it has been implemented in python and why it is implemented that way.
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