Tutorial by Examples: u

['cat', 'dog', 'fish'].collect { it.length() } it is the default name of the parameter if you have a single parameter and do not explicitly name the parameter. You can optionally declare the parameter as well. ['cat', 'dog', 'fish'].collect { animal -> animal.length() }

Groovy has access to all java classes, in fact Groovy classes ARE Java classes and can be run by the JVM directly. If you are working on a Java project, using Groovy as a simple scripting language to interact with your java code is a no-brainer. To make things even better, nearly any Java class ca...

When given an argument, the when-statement matches the argument against the branches in sequence. The matching is done using the == operator which performs null checks and compares the operands using the equals function. The first matching one will be executed. when (x) { "English" -...

(This pitfall applies equally to all primitive wrapper types, but we will illustrate it for Integer and int.) When working with Integer objects, it is tempting to use == to compare values, because that is what you would do with int values. And in some cases this will seem to work: Integer int1_1 =...

Custom constructors can be made for derived types by using an interface to overload the type name. This way, keyword arguments that don't correspond to components can be used when constructing an object of that type. module ball_mod implicit none ! only export the derived type, and not any ...

The .format() method can interpret a number in different formats, such as: >>> '{:c}'.format(65) # Unicode character 'A' >>> '{:d}'.format(0x0a) # base 10 '10' >>> '{:n}'.format(0x0a) # base 10 using current locale for separators '10' Format integers to d...

union U { int a; short b; float c; }; U u; u.a = 10; if (u.b == 10) { // this is undefined behavior since 'a' was the last member to be // written to. A lot of compilers will allow this and might issue a // warning, but the result will be "as expected"; thi...

Properties can be set when an object is instantiated. var redCar = new Car { Wheels = 2, Year = 2016, Color = Color.Red };

If you need to know whether a value's type extends or implements a given type, but you don't want to actually cast it as that type, you can use the is operator. if(value is int) { Console.WriteLine(value + "is an int"); }

Explicit casting operators can be used to perform conversions of numeric types, even though they don't extend or implement one another. double value = -1.1; int number = (int) value; Note that in cases where the destination type has less precision than the original type, precision will be lost....

public class Singleton { private static class InstanceHolder { static final Singleton INSTANCE = new Singleton(); } public static Singleton getInstance() { return InstanceHolder.INSTANCE; } private Singleton() {} } This initializes the INSTANCE vari...

add_action('init' , function(){ echo 'i did something'; });

Getting all the information of current user in wordpress using the predefined function wp_get_current_user(); <?php $current_user = wp_get_current_user(); echo "Username :".$current_user->user_login; echo "Username :".$current_user-&g...

function social_profiles( $contactmethods ) { $contactmethods['facebook_profile'] = 'Facebook Profile URL'; $contactmethods['twitter_profile'] = 'Twitter Profile URL'; $contactmethods['google_profile'] = 'Google Profile URL'; $contactmethods['linkedin_profile'] = 'Li...

OpenSSL is an open source project that provides a robust, commercial-grade, and full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It is also a general-purpose cryptography library. The OpenSSL toolkit is licensed under an Apache-style license, wh...

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...

Detailed instructions on getting math set up or installed.

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...