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Why is it slower to iterate over a small string than a small list?
...nd with timeit and noticed that doing a simple list comprehension over a small string took longer than doing the same operation on a list of small single character strings. Any explanation? It's almost 1.35 times as much time.
...
What is the difference between sigaction and signal?
...ion() avoids - unless you use the flags explicitly added to sigaction() to allow it to faithfully simulate the old signal() behaviour.
The signal() function does not (necessarily) block other signals from arriving while the current handler is executing; sigaction() can block other signals until the...
What is DOM Event delegation?
...ame effect.
So what's the benefit?
Imagine you now have a need to dynamically add new <li> items to the above list via DOM manipulation:
var newLi = document.createElement('li');
newLi.innerHTML = 'Four';
myUL.appendChild(newLi);
Without using event delegation you would have to "rebind" t...
Generating an MD5 checksum of a file
...ing (and checking) MD5 checksums of a list of files in Python? (I have a small program I'm working on, and I'd like to confirm the checksums of the files).
...
Pass a data.frame column name to a function
...l_name,col1,col2){
df$col_name <- df$col1 + df$col2
df
}
#Call foo() like this:
foo(dat,z,x,y)
The problem here is that df$col1 doesn't evaluate the expression col1. It simply looks for a column in df literally called col1. This behavior is described in ?Extract under the secti...
What's the difference between using “let” and “var”?
...does not create a property on the global object:
var foo = "Foo"; // globally scoped
let bar = "Bar"; // globally scoped
console.log(window.foo); // Foo
console.log(window.bar); // undefined
Redeclaration
In strict mode, var will let you re-declare the same variable in the same scope while let...
Using HTML5/Canvas/JavaScript to take in-browser screenshots
...mplementation of it into sending feedbacks like you described.
The script allows you to create feedback forms which include a screenshot, created on the client's browser, along with the form. The screenshot is based on the DOM and as such may not be 100% accurate to the real representation as it do...
In HTML5, should the main navigation be inside or outside the element?
...element is for navigation around that site only. I was just being clear is all.
– Ian Devlin
Feb 2 '11 at 16:54
@Matth...
How to create an object for a Django model with a many to many field?
...
For future visitors, you can create an object and all of its m2m objects in 2 queries using the new bulk_create in django 1.4. Note that this is only usable if you don't require any pre or post-processing on the data with save() methods or signals. What you insert is exactly...
What does the thread_local mean in C++11?
...al variables in a function. The global/static variables can be accessed by all the threads (possibly synchronized access using locks). And the thread_local variables are visible to all the threads but can only modified by the thread for which they are defined? Is it correct?
...