Tutorial by Examples: d

class sample{ public static function add_action_func(){ //note __CLASS__ will also include any namespacing add_action('init', array(__CLASS__, 'samp') ); } public static function samp(){ echo 'i did something'; } } sample::add_a...

function remove_contact_methods( $contactmethods ) { unset($contactmethods['facebook_profile']); unset($contactmethods['twitter_profile']); return $contactmethods; } add_filter( 'user_contactmethods', 'remove_contact_methods', 10, 1);

Most browsers, when configured to block cookies, will also block localStorage. Attempts to use it will result in an exception. Do not forget to manage these cases. var video = document.querySelector('video') try { video.volume = localStorage.getItem('volume') } catch (error) { alert('If...

It is sometimes useful to verify that your work on Developer edition hasn't introduced a dependency on any features restricted to Enterprise edition. You can do this using the sys.dm_db_persisted_sku_features system view, like so: SELECT * FROM sys.dm_db_persisted_sku_features Against the datab...

data(AirPassengers) class(AirPassengers) 1 "ts" In the spirit of Exploratory Data Analysis (EDA) a good first step is to look at a plot of your time-series data: plot(AirPassengers) # plot the raw data abline(reg=lm(AirPassengers~time(AirPassengers))) # fit a trend line For...

generate sample DF In [39]: df = pd.DataFrame(np.random.randint(0, 10, size=(5, 6)), columns=['a10','a20','a25','b','c','d']) In [40]: df Out[40]: a10 a20 a25 b c d 0 2 3 7 5 4 7 1 3 1 5 7 2 6 2 7 4 9 0 8 7 3 5 8 8 9 6 8 4 8 1 ...

from datetime import datetime import pandas_datareader.data as wb stocklist = ['AAPL','GOOG','FB','AMZN','COP'] start = datetime(2016,6,8) end = datetime(2016,6,11) p = wb.DataReader(stocklist, 'yahoo',start,end) p - is a pandas panel, with which we can do funny things: let's see what...

import os import glob import pandas as pd def get_merged_csv(flist, **kwargs): return pd.concat([pd.read_csv(f, **kwargs) for f in flist], ignore_index=True) path = 'C:/Users/csvfiles' fmask = os.path.join(path, '*mask*.csv') df = get_merged_csv(glob.glob(fmask), index_col=None, use...

You can iterate on the object returned by groupby(). The iterator contains (Category, DataFrame) tuples. # Same example data as in the previous example. import numpy as np import pandas as pd np.random.seed(0) df = pd.DataFrame({'Age': np.random.randint(20, 70, 100), 'Sex':...

@org.junit.Test public void should_$name$() { $END$ } Make sure to check the Shorted FQ names box when creating this template. When you type "should" (the abbreviation), this will add the necessary import org.junit.Test; statement at the top of the file, and this code: @Test...

Imagine a goroutine with a two step process, where the main thread needs to do some work between each step: func main() { ch := make(chan struct{}) go func() { // Wait for main thread's signal to begin step one <-ch // Perform work time.Sle...

Unlike a named class or struct, unnamed classes and structs must be instantiated where they are defined, and cannot have constructors or destructors. struct { int foo; double bar; } foobar; foobar.foo = 5; foobar.bar = 4.0; class { int baz; public: int buzz; ...

extern crate serde; extern crate serde_json; #[macro_use] extern crate serde_derive; use std::collections::BTreeMap as Map; #[derive(Serialize)] struct Resource { // Always serialized. name: String, // Never serialized. #[serde(skip_serializing)] hash: String, ...

mutable modifier in this context is used to indicate that a data field of a const object may be modified without affecting the externally-visible state of the object. If you are thinking about caching a result of expensive computation, you should probably use this keyword. If you have a lock (for ...

By default, the implicit operator() of a lambda is const. This disallows performing non-const operations on the lambda. In order to allow modifying members, a lambda may be marked mutable, which makes the implicit operator() non-const: int a = 0; auto bad_counter = [a] { return a++; // er...

Maps and keyword lists have different application. For instance, a map cannot have two keys with the same value and it's not ordered. Conversely, a Keyword list can be a little bit hard to use in pattern matching in some cases. Here's a few use cases for maps vs keyword lists. Use keyword lists wh...

You can also use the IEx (Interactive Elixir) shell to evaluate expressions and execute code. If you are on Linux or Mac, just type iex on your bash and press enter: $ iex If you are on a Windows machine, type: C:\ iex.bat Then you will enter into the IEx REPL (Read, Evaluate, Print, Loop),...

When you document your code with @doc, you can supply code examples like so: # myproject/lib/my_module.exs defmodule MyModule do @doc """ Given a number, returns `true` if the number is even, otherwise `false`. ## Example iex> MyModule.even?(2) true ie...

The code listing below attempts to classify handwritten digits from the MNIST dataset. The digits look like this: The code will preprocess these digits, converting each image into a 2D array of 0s and 1s, and then use this data to train a neural network with upto 97% accuracy (50 epochs). "...

struct FileAttributes { unsigned int ReadOnly: 1; unsigned int Hidden: 1; }; Here, each of these two fields will occupy 1 bit in memory. It is specified by : 1 expression after the variable names. Base type of bit field could be any integral type (8-bit int to 64-bit int). Using u...