Tutorial by Examples

Sometimes, you may want something to occur regardless of whatever exception happened, for example, if you have to clean up some resources. The finally block of a try clause will happen regardless of whether any exceptions were raised. resource = allocate_some_expensive_resource() try: do_stu...

Sometimes you want to catch an exception just to inspect it, e.g. for logging purposes. After the inspection, you want the exception to continue propagating as it did before. In this case, simply use the raise statement with no parameters. try: 5 / 0 except ZeroDivisionError: print(&quo...

In the process of handling an exception, you may want to raise another exception. For example, if you get an IOError while reading from a file, you may want to raise an application-specific error to present to the users of your library, instead. Python 3.x3.0 You can chain exceptions to show how t...

Exception handling occurs based on an exception hierarchy, determined by the inheritance structure of the exception classes. For example, IOError and OSError are both subclasses of EnvironmentError. Code that catches an IOError will not catch an OSError. However, code that catches an EnvironmentErr...

Exceptions are just regular Python objects that inherit from the built-in BaseException. A Python script can use the raise statement to interrupt execution, causing Python to print a stack trace of the call stack at that point and a representation of the exception instance. For example: >>&gt...

Download and install the latest IDEA version. Download and install the latest version of the Cursive plugin. After restarting IDEA, Cursive should be working out of the box. Follow the user guide to fine-tune appearance, keybindings, code style etc. Note: Like IntelliJ, Cursive is a commercial pr...

Suggested Install Method Windows: Download and run the binary setup file. Linux(Debian): Run this command in your command line: $ apt-get install python-qt4 pyqt4-dev-tools qt4-designer OS X : Run this command in your command line: $ brew install pyqt Install Manually You can also downloa...

If you would like to stash only some diffs in your working set, you can use a partial stash. git stash -p And then interactively select which hunks to stash. As of version 2.13.0 you can also avoid the interactive mode and create a partial stash with a pathspec using the new push keyword. git ...

If I wanted to find out the sum of numbers from 1 to n where n is a natural number, I can do 1 + 2 + 3 + 4 + ... + (several hours later) + n. Alternatively, I could write a for loop: n = 0 for i in range (1, n+1): n += i Or I could use a technique known as recursion: def recursion(n): ...

While reading content from a file is already asynchronous using the fs.readFile() method, sometimes we want to get the data in a Stream versus in a simple callback. This allows us to pipe this data to other locations or to process it as it comes in versus all at once at the end. const fs = require(...

App.xaml.cs file (App.xaml file is default, so skipped) using Xamrin.Forms namespace NavigationApp { public partial class App : Application { public static INavigation GlobalNavigation { get; private set; } public App() { InitializeComponent()...

You can perform redirection in Rails routes as follows: 4.0 get '/stories', to: redirect('/posts') 4.0 match "/abc" => redirect("http://example.com/abc") You can also redirect all unknown routes to a given path: 4.0 match '*path' => redirect('/'), via: :get ...

To find some number (more than one) of largest or smallest values of an iterable, you can use the nlargest and nsmallest of the heapq module: import heapq # get 5 largest items from the range heapq.nlargest(5, range(10)) # Output: [9, 8, 7, 6, 5] heapq.nsmallest(5, range(10)) # Output: [...

// get some data from stackoverflow fetch("https://api.stackexchange.com/2.2/questions/featured?order=desc&sort=activity&site=stackoverflow") .then(resp => resp.json()) .then(json => console.log(json)) .catch(err => console.log(err));

The typical example is an abstract shape class, that can then be derived into squares, circles, and other concrete shapes. The parent class: Let's start with the polymorphic class: class Shape { public: virtual ~Shape() = default; virtual double get_surface() const = 0; virtual vo...

Packages are collections of R functions, data, and compiled code in a well-defined format. Public (and private) repositories are used to host collections of R packages. The largest collection of R packages is available from CRAN. Using CRAN A package can be installed from CRAN using following code...

To install package from local source file: install.packages(path_to_source, repos = NULL, type="source") install.packages("~/Downloads/dplyr-master.zip", repos=NULL, type="source") Here, path_to_source is absolute path of local source file. Another command that ...

Here is a full Activity class that places a Marker at the current location, and also moves the camera to the current position. There are a few thing going on in sequence here: Check Location permission Once Location permission is granted, call setMyLocationEnabled(), build the GoogleApiClient, ...

Definition of Decorator as per Wikiepdia: The Decorator pattern can be used to extend (decorate) the functionality of a certain object statically, or in some cases at run-time, independently of other instances of the same class, provided some groundwork is done at design time. Decorator attach add...

Django makes it really easy to add additional data onto requests for use within the view. For example, we can parse out the subdomain on the request's META and attach it as a separate property on the request by using middleware. class SubdomainMiddleware: def process_request(self, request): ...