Tutorial by Examples: le

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...

While The most trivial loop type. Only drawback is there is no intrinsic clue to know where you are in the loop. /// loop while the condition satisfies while(condition) { /// do something } Do Similar to while, but the condition is evaluated at the end of the loop instead of the beginn...

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Files and directories (another name for folders) are at the heart of Linux, so being able to create, view, move, and delete them from the command line is very important and quite powerful. These file manipulation commands allow you to perform the same tasks that a graphical file explorer would perfo...

Use the HTML or <audio> element to embed video/audio content in a document. The video/audio element contains one or more video/audio sources. To specify a source, use either the src attribute or the <source> element; the browser will choose the most suitable one. Audio tag example: &...

You can open several content managers at the same time: with open(input_path) as input_file, open(output_path, 'w') as output_file: # do something with both files. # e.g. copy the contents of input_file into output_file for line in input_file: output_file.write(line...

Install the necessary Python Library via: $ pip install elasticsearch Connect to Elasticsearch, Create a Document (e.g. data entry) and "Index" the document using Elasticsearch. from datetime import datetime from elasticsearch import Elasticsearch # Connect to Elasticsearch using ...

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!" ...

.Net 4.0 type Lazy guarantees thread-safe object initialization, so this type could be used to make Singletons. public class LazySingleton { private static readonly Lazy<LazySingleton> _instance = new Lazy<LazySingleton>(() => new LazySingleton()); public stati...

Instead of requesting an ILoggerFactory and creating an instance of ILogger explicitly, you can request an ILogger (where T is the class requesting the logger). public class TodoController : Controller { private readonly ILogger _logger; public TodoController(ILogger<TodoController...

For ease of testing, sklearn provides some built-in datasets in sklearn.datasets module. For example, let's load Fisher's iris dataset: import sklearn.datasets iris_dataset = sklearn.datasets.load_iris() iris_dataset.keys() ['target_names', 'data', 'target', 'DESCR', 'feature_names'] You can ...

Consider this simple class: class SmsUtil { public bool SendMessage(string from, string to, string message, int retryCount, object attachment) { // Some code } } Before C# 3.0 it was: var result = SmsUtil.SendMessage("Mehran", "Maryam", "Hello...

setTimeout Executes a function, after waiting a specified number of milliseconds. used to delay the execution of a function. Syntax : setTimeout(function, milliseconds) or window.setTimeout(function, milliseconds) Example : This example outputs "hello" to the console after 1 secon...

Normal types, like String, are not nullable. To make them able to hold null values, you have to explicitly denote that by putting a ? behind them: String? var string : String = "Hello World!" var nullableString: String? = null string = nullableString // Compiler error: Can't...

Ruby Standard Library has a Singleton module which implements the Singleton pattern. The first step in creating a Singleton class is to require and include the Singleton module in a class: require 'singleton' class Logger include Singleton end If you try to instantiate this class as you n...

If need set value 0 to column B, where in column A are duplicated data first create mask by Series.duplicated and then use DataFrame.ix or Series.mask: In [224]: df = pd.DataFrame({'A':[1,2,3,3,2], ...: 'B':[1,7,3,0,8]}) In [225]: mask = df.A.duplicated(keep=False) In...

When working with regular expressions one modifier for PCRE is g for global match. In R matching and replacement functions have two version: first match and global match: sub(pattern,replacement,text) will replace the first occurrence of pattern by replacement in text gsub(pattern,replace...