Tutorial by Examples: b

When you inherit from a class with a property, you can provide a new implementation for one or more of the property getter, setter or deleter functions, by referencing the property object on the parent class: class BaseClass(object): @property def foo(self): return some_calculate...

The following example listens to window.onerror event and uses an image beacon technique to send the information through the GET parameters of an URL. var hasLoggedOnce = false; // Some browsers (at least Firefox) don't report line and column numbers // when event is handled through window.addE...

Attributes are name-value pairs associated with an element. They are represented by values in single or double quotes inside the opening element tag, or the empty element tag if it is an empty element. <document> <anElement foo="bar" abc='xyz'><!-- some content -->&l...

we can annotate fields with @BindView and a view ID for Butter Knife to find and automatically cast the corresponding view in our layout. Binding Views Binding Views in Activity class ExampleActivity extends Activity { @BindView(R.id.title) TextView title; @BindView(R.id.subtitle) TextView ...

Import the numpy module to use any part of it. import numpy as np Most examples will use np as shorthand for numpy. Assume "np" means "numpy" in code examples. x = np.array([1,2,3,4])

This makes image masked to the shape of the letters of the label: Objective-C self.maskImage.layer.mask = self.maskLabel.layer; self.maskImage.layer.masksToBounds = YES; Swift 3 maskImageView.mask = maskLabel maskImageView.masksToBounds = true Here is the result:

arr = np.arange(7) print(arr) # Out: array([0, 1, 2, 3, 4, 5, 6]) Comparison with a scalar returns a boolean array: arr > 4 # Out: array([False, False, False, False, False, True, True], dtype=bool) This array can be used in indexing to select only the numbers greater than 4: arr[arr&...

Along with classic way of route definition MVC WEB API 2 and then MVC 5 frameworks introduced Attribute routing: public class RouteConfig { public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); // This...

Draw samples from a normal (gaussian) distribution # Generate 5 random numbers from a standard normal distribution # (mean = 0, standard deviation = 1) np.random.randn(5) # Out: array([-0.84423086, 0.70564081, -0.39878617, -0.82719653, -0.4157447 ]) # This result can also be achieved with t...

In the condition of the for and while loops, it's also permitted to declare an object. This object will be considered to be in scope until the end of the loop, and will persist through each iteration of the loop: for (int i = 0; i < 5; ++i) { do_something(i); } // i is no longer in scope...

The following method computes the Nth Fibonacci number using recursion. public int fib(final int n) { if (n > 2) { return fib(n - 2) + fib(n - 1); } return 1; } The method implements a base case (n <= 2) and a recursive case (n>2). This illustrates the use of re...

If your class doesn't implement a specific overloaded operator for the argument types provided, it should return NotImplemented (note that this is a special constant, not the same as NotImplementedError). This will allow Python to fall back to trying other methods to make the operation work: When...

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By recursion let rec sumTotal list = match list with | [] -> 0 // empty list -> return 0 | head :: tail -> head + sumTotal tail The above example says: "Look at the list, is it empty? return 0. Otherwise it is a non-empty list. So it could be [1], [1; 2], [1; 2; 3] ...

Code that uses generics has many benefits over non-generic code. Below are the main benefits Stronger type checks at compile time A Java compiler applies strong type checking to generic code and issues errors if the code violates type safety. Fixing compile-time errors is easier than fixing runt...

Example uses basic HTTP syntax. Any <#> in the example should be removed when copying it. You can use the _cat APIs to get a human readable, tabular output for various reasons. GET /_cat/health?v <1> The ?v is optional, but it implies that you want "verbose" output. _...

One can select rows and columns of a dataframe using boolean arrays. import pandas as pd import numpy as np np.random.seed(5) df = pd.DataFrame(np.random.randint(100, size=(5, 5)), columns = list("ABCDE"), index = ["R" + str(i) for i in range(5)]) print (...

data.table offers a wide range of possibilities to reshape your data both efficiently and easily For instance, while reshaping from long to wide you can both pass several variables into the value.var and into the fun.aggregate parameters at the same time library(data.table) #v>=1.9.6 DT <- ...

The ** operator works similarly to the * operator but it applies to keyword parameters. def options(required_key:, optional_key: nil, **other_options) other_options end options(required_key: 'Done!', foo: 'Foo!', bar: 'Bar!') #> { :foo => "Foo!", :bar => "Bar!" ...

impl<'a> Type<'a> { fn my_function(&self) -> &'a u32 { self.x } } This specifies that Type has lifetime 'a, and that the reference returned by my_function() may no longer be valid after 'a ends because the Type no longer exists to hold self.x.