Accessing the index in ‘for’ loops?

Using an additional state variable, such as an index variable (which you would normally use in languages such as C or PHP), is considered non-pythonic. The better option is to use the built-in function enumerate(), available in both Python 2 and 3:

How to create a GUID/UUID in Python

The uuid module provides immutable UUID objects (the UUID class) and the functions uuid1(), uuid3(), uuid4(), uuid5() for generating version 1, 3, 4, and 5 UUIDs as specified in RFC 4122. If all you want is a unique ID, you should probably call uuid1() or uuid4(). Note that uuid1() may compromise privacy since it creates a UUID containing … Read more

How do I redirect to another webpage?

One does not simply redirect using jQuery jQuery is not necessary, and window.location.replace(…) will best simulate an HTTP redirect. window.location.replace(…) is better than using window.location.href, because replace() does not keep the originating page in the session history, meaning the user won’t get stuck in a never-ending back-button fiasco. If you want to simulate someone clicking on a link, use location.href If you … Read more

Why should we typedef a struct so often in C?

As Greg Hewgill said, the typedef means you no longer have to write struct all over the place. That not only saves keystrokes, it also can make the code cleaner since it provides a smidgen more abstraction. Stuff like becomes cleaner when you don’t need to see the “struct” keyword all over the place, it looks more … Read more

What’s the meaning of “=>” (an arrow formed from equals & greater than) in JavaScript?

What It Is This is an arrow function. Arrow functions are a short syntax, introduced by ECMAscript 6, that can be used similarly to the way you would use function expressions. In other words, you can often use them in place of expressions like function (foo) {…}. But they have some important differences. For example, they do … Read more

Start script missing error when running npm start

It looks like you might not have defined a start script in your package.json file or your project does not contain a server.js file. If there is a server.js file in the root of your package, then npm will default the start command to node server.js. You could either change the name of your application script to server.js or add the following to … Read more

CSS Background Opacity [duplicate]

Children inherit opacity. It’d be weird and inconvenient if they didn’t. You can use a translucent PNG file for your background image, or use an RGBa (a for alpha) color for your background color. Example, 50% faded black background:

Regex not operator

No, there’s no direct not operator. At least not the way you hope for. You can use a zero-width negative lookahead, however: The (?!…) part means “only match if the text following (hence: lookahead) this doesn’t (hence: negative) match this. But it doesn’t actually consume the characters it matches (hence: zero-width). There are actually 4 combinations of lookarounds with 2 axes: lookbehind / lookahead : … Read more