Tutorial by Examples: co

Color state lists can be used as colors, but will change depending on the state of the view they are used for. To define one, create a resource file in res/color/foo.xml <?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/ap...

import pandas as pd import numpy as np np.random.seed(123) x = np.random.standard_normal(4) y = range(4) df = pd.DataFrame({'X':x, 'Y':y}) >>> df X Y 0 -1.085631 0 1 0.997345 1 2 0.282978 2 3 -1.506295 3

A select case construct conditionally executes one block of constructs or statements depending on the value of a scalar expression in a select case statement. This control construct can be considered as a replacement for computed goto. [name:] SELECT CASE (expr) [CASE (case-value [, case-value] .....

Component code: angular.module('myModule', []).component('myComponent', { bindings: { myValue: '<' }, controller: function(MyService) { this.service = MyService; this.componentMethod = function() { return 2; }; } }); The test: describe('myComponent', f...

Oracle's CONNECT BY functionality provides many useful and nontrivial features that are not built-in when using SQL standard recursive CTEs. This example replicates these features (with a few additions for sake of completeness), using SQL Server syntax. It is most useful for Oracle developers findin...

An implicit conversion allows the compiler to automatically convert an object of one type to another type. This allows the code to treat an object as an object of another type. case class Foo(i: Int) // without the implicit Foo(40) + 2 // compilation-error (type mismatch) // defines how t...

Constants can be defined inside classes using a const keyword. class Foo { const BAR_TYPE = "bar"; // reference from inside the class using self:: public function myMethod() { return self::BAR_TYPE; } } // reference from outside the class using <Class...

Introduction: This simple function generates infinite series of numbers. For example... for number in itertools.count(): if number > 20: break print(number) Note that we must break or it prints forever! Output: 0 1 2 3 4 5 6 7 8 9 10 Arguments: count() ta...

There are a couple of ways to delete a column in a DataFrame. import numpy as np import pandas as pd np.random.seed(0) pd.DataFrame(np.random.randn(5, 6), columns=list('ABCDEF')) print(df) # Output: # A B C D E F # 0 -0.895467 0.386902...

Returns a Boolean indicating if the class conform the protocol: [MyClass conformsToProtocol:@protocol(MyProtocol)];

Due to Node's asynchronous nature, creating or using a directory by first: checking for its existence with fs.stat(), then creating or using it depending of the results of the existence check, can lead to a race condition if the folder is created between the time of the check and the time of ...

The nodemon package makes it possible to automatically reload your program when you modify any file in the source code. Installing nodemon globally npm install -g nodemon (or npm i -g nodemon) Installing nodemon locally In case you don't want to install it globally npm install --save-dev nodemo...

Say we have an enum DayOfWeek: enum DayOfWeek { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY; } An enum is compiled with a built-in static valueOf() method which can be used to lookup a constant by its name: String dayName = DayOfWeek.SUNDAY.name(); assert dayName.equal...

The following code will print the arguments to the program, and the code will attempt to convert each argument into a number (to a long): #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <limits.h> int main(int argc, char* argv[]) { for (int ...

Defining a member block inside a resource creates a route that can act on an individual member of that resource-based route: resources :posts do member do get 'preview' end end This generates the following member route: get '/posts/:id/preview', to: 'posts#preview' # preview_post_p...

If you are building a function that may be heavy on the processor (either clientside or serverside) you may want to consider a memoizer which is a cache of previous function executions and their returned values. This allows you to check if the parameters of a function were passed before. Remember, p...

# Create a sample DF df = pd.DataFrame(np.random.randn(5, 3), columns=list('ABC')) # Show DF df A B C 0 -0.467542 0.469146 -0.861848 1 -0.823205 -0.167087 -0.759942 2 -1.508202 1.361894 -0.166701 3 0.394143 -0.287349 -0.978102 4 -0.160431 1.054736 -0.785250 ...

:root { --red: #b00; --blue: #4679bd; --grey: #ddd; } .Bx1 { color: var(--red); background: var(--grey); border: 1px solid var(--red); }

Raw direct IO file_get_contents and file_put_contents provide the ability to read/write from/to a file to/from a PHP string in a single call. file_put_contents can also be used with the FILE_APPEND bitmask flag to append to, instead of truncate and overwrite, the file. It can be used along with LO...

child.py import time def main(): print "starting work" time.sleep(1) print "work work work work work" time.sleep(1) print "done working" if __name__ == '__main__': main() parent.py import os def main(): for i in range(5):...