Why does indentation matter? In Python, indentation is used to delimit blocks of code. This is different from many other languages that use curly braces {} to delimit blocks such as Java, Javascript, and C. Because of this, Python users must pay close attention to when and how they indent their code because whitespace matters. … Read more
Many people say that checked exceptions (i.e. these that you should explicitly catch or rethrow) should not be used at all. They were eliminated in C# for example, and most languages don’t have them. So you can always throw a subclass of RuntimeException (unchecked exception) However, I think checked exceptions are useful – they are … Read more
Parameters and local variables are allocated on the stack (with reference types, the object lives on the heap and a variable in the stack references that object on the heap). The stack typically lives at the upper end of your address space and as it is used up it heads towards the bottom of the … Read more
This happens because your local module named requests.py shadows the installed requests module you are trying to use. The current directory is prepended to sys.path, so the local name takes precedence over the installed name. An extra debugging tip when this comes up is to look at the Traceback carefully, and realize that the name … Read more
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 … Read more
Your first port of call should be the documentation which explains it reasonably clearly: Thrown to indicate that an array has been accessed with an illegal index. The index is either negative or greater than or equal to the size of the array. So for example: int[] array = new int[5]; int boom = array[10]; … Read more
Are you saying you want to have reference to the original exception when you rescue the second exception? If so, then you need to capture the original exception in a variable during the rescue. This is done by doing: rescue StandardError => e where StandardError can be any type of exception or omitted (in which … Read more
try { int userValue = Integer.parseInt(aString); } catch (NumberFormatException e) { //there you go } and specifically in your code: public void actionPerformed(ActionEvent e) { String str; int no; //———————————— try { //lots of ifs here } catch (NumberFormatException e) { //do something with the exception you caught } if (e.getSource() == finish) { if … Read more