Of course the “You shall not instantiate an item of this class” statement has been violated, but if this is the logic behind that, then we should all throw AssertionErrors everywhere, and that is obviously not what happens. The code isn’t saying the user shouldn’t call the zero-args constructor. The assertion is there to say that as far as … Read more
If you try to decrypt PKCS5-padded data with the wrong key, and then unpad it (which is done by the Cipher class automatically), you most likely will get the BadPaddingException (with probably of slightly less than 255/256, around 99.61%), because the padding has a special structure which is validated during unpad and very few keys … Read more
The error means that the string you’re trying to parse an integer from doesn’t actually contain a valid integer. It’s extremely unlikely that the text boxes will contain a valid integer immediately when the form is created – which is where you’re getting the integer values. It would make much more sense to update a and b in the … Read more
I am trying to create a JavaFX program, and every time I try to run my code I am getting an exception – I’m not entirely sure what it means though… My code: Stack trace: Any help will be appreciated, Thanks Ask Question
I’d suggest checking for an inner exception. If there isn’t one, check your logs for the exception that occurred immediately prior to this one. This isn’t a web-specific exception, I’ve also encountered it in desktop-app development. In short, what’s happening is that the thread receiving this exception is running some asynchronous code (via Invoke(), e.g.) … Read more
Maybe I missed the question, but why not: To override something (or pass extra args), do this: That way you could pass dict of error messages to the second param, and get to it later with e.errors. In Python 2, you have to use this slightly more complex form of super():
You can but you probably shouldn’t: However, this will also catch exceptions like KeyboardInterrupt and you usually don’t want that, do you? Unless you re-raise the exception right away – see the following example from the docs:
You have to define which type of exception you want to catch. So write except Exception, e: instead of except, e: for a general exception (that will be logged anyway). Other possibility is to write your whole try/except code this way: in Python 3.x and modern versions of Python 2.x use except Exception as e instead of except Exception, e:
Background: What’s an Optional? In Swift, Optional<Wrapped> is an option type: it can contain any value from the original (“Wrapped”) type, or no value at all (the special value nil). An optional value must be unwrapped before it can be used. Optional is a generic type, which means that Optional<Int> and Optional<String> are distinct types — the type inside <> is called the Wrapped type. Under the hood, … Read more
To check the existence of a local variable: To check the existence of a global variable: To check if an object has an attribute: