Programming Articles - Page 2093 of 3363

Move all zeroes to end of the array using List Comprehension in Python

Hafeezul Kareem
Updated on 12-Feb-2020 11:44:21

2K+ Views

Given a list of numbers, move all the zeroes to the end using list comprehensions. For example, the result of [1, 3, 0, 4, 0, 5, 6, 0, 7] is [1, 3, 4, 5, 6, 7, 0, 0, 0].It's a single line code using the list comprehensions. See the following steps to achieve the result.Initialize the list of numbers.Generate non-zeroes from the list and generate zeroes from the list. Add both. And store the result in a list.Print the new list.Example# initializing a list numbers = [1, 3, 0, 4, 0, 5, 6, 0, 7] # moving all the zeroes ... Read More

Merge, Join and Concatenate DataFrames using Pandas

Hafeezul Kareem
Updated on 12-Feb-2020 11:42:34

1K+ Views

In this tutorial, we are going to learn to merge, join, and concat the DataFrames using pandas library. I think you are already familiar with dataframes and pandas library. Let's see the three operations one by one.MergeWe have a method called pandas.merge() that merges dataframes similar to the database join operations. Follow the below steps to achieve the desired output. Merge method uses the common column for the merge operation.Initialize the Dataframes.Call the method pandas.merge() with three arguments dataframes, how (defines the database join operation), on (common field of the dataframes).ExampleLet's see an example.# importing the pandas library import pandas # creating dataframes   ... Read More

Get a google map image of specified location using Google Static Maps API in Python

Hafeezul Kareem
Updated on 12-Feb-2020 11:29:57

4K+ Views

Google provides a static maps API that returns a map image on our HTTP request. We can directly request for a map image with different parameters based on our need.We have to create a billing account on Google to use this API. You can go to the website for more details.Let's see the steps to get the image of a location.Import the requests module.Initialise your API Key and base URL ("https://maps.googleapis.com/maps/api/staticmap?").Initialize the city and zoom value.Update the URL with API Key, City, and Zoom value.USend an HTTP request. And write the response to a file for saving the image.pdate the ... Read More

Find current weather of any city using OpenWeatherMap API in Python

Hafeezul Kareem
Updated on 12-Feb-2020 11:25:39

9K+ Views

In this tutorial, we are going to get the weather of a city using OpenWeatherMap API. To use the OpenWeatherMap API, we have to get the API key. We will get it by creating an account on their website.Create an account and get your API Key. It's free until 60 calls per minute. You have to pay if you want more than that. For this tutorial, the free version is enough. We need requests module for the HTTP requests and JSON module to work with the response. Follow the below steps to the weather of any city.Import the requests and JSON ... Read More

Count frequencies of all elements in array in Python

Hafeezul Kareem
Updated on 12-Feb-2020 11:16:43

20K+ Views

In this tutorial, we are going to write a program that finds the frequency of all the elements in an array. We can find it in different ways let's explore two of them.Using dictInitialize the array.Initialize an empty dict.Iterate over the list.If the element is not in dict, then set the value to 1.Else increment the value by 1.Print the element and frequencies by iterating over the dict.ExampleLet's see the code.# intializing the list arr = [1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3] # initializing dict to store frequency of each element elements_count = {} ... Read More

Count all prefixes in given string with greatest frequency using Python

Hafeezul Kareem
Updated on 12-Feb-2020 11:10:44

653 Views

In this tutorial, we are going to write a program that counts and prints the words with a higher frequency of an alphabet than the second one.Take a string and two alphabets. The prefixes with a higher frequency of the first alphabet will be printed. And display the count at the end of the output.Let's see some examples.Inputstring:- apple alphabets:- p, eOutputap app appl apple 4Inputstring:- apple alphabets:- e, pOutput0Let's see the steps to write the code.Define a function and write the code in it.Initialize count to 0 and an empty string.Iterate over the string.Get the prefix using the string ... Read More

What are the new features added to Stream API in Java 9?

raja
Updated on 21-Feb-2020 12:20:30

209 Views

In Java 9, Oracle Corporation has added four useful new methods to Stream API. Those methods are iterate(), ofNullable(), takeWhile() and dropWhile().iterate()The iterate() can be used as stream version replacement of traditional for-loops. This method has improved by adding another parameter, the Predicate interface that allows us to stop these endless numbers based on conditions defined with the Predicate interface.Exampleimport java.util.stream.Stream; public class StreamIterateMethodTest {    public static void main(String[] args) {       Stream.iterate(1, i -> i < 5, i -> i + 1).forEach(System.out::println); // iterate()    } }Output1 2 3 4ofNullable()The ofNullable() method returns the stream object of an element if it ... Read More

What are the new methods added to an Optional class in Java 9?

raja
Updated on 21-Feb-2020 12:21:47

320 Views

An Optional class provides a container that may or may not contain a non-null value. This Optional class introduced in Java 8 to reduce the number of places in the code where a NullPointerException can be generated. Java 9 added three new methods to Optional class: or(), ifPresentOrElse() and stream() that help us to deal with default values.Optional.or()The or() method introduced in Java 9 and the parameter of this method is a functional interface Supplier. This method always gives us an Optional object that is not empty. If the Optional object is not empty, it returns the Optional object itself. Otherwise, it returns an Optional ... Read More

What are the rules for private methods in an interface in Java 9?

raja
Updated on 21-Feb-2020 12:43:46

1K+ Views

Java 9 added a new feature of private methods to an interface. The private methods can be defined using a private modifier. We can add both private and private static methods in an interface from Java 9 onwards.Rules for private methods in an interface:A private method has a body in an interface means that we can’t be declared as a normal abstract method as usually do in an interface. If we are trying to declare a private method without a body then it can throw an error says that "This method requires a body instead of a semicolon".We can't be used both private and abstract modifiers together in an interface.If ... Read More

What are the main features and enhancements introduced in Java 9?

raja
Updated on 11-Feb-2020 08:00:28

302 Views

Oracle has released Java 9 version with a rich set of new features and brings a lot of new enhancements.Below are a few important features and enhancements introduced in Java 9.Factory Methods for Collections: Factory methods are special kinds of static methods that can be used to create unmodifiable instances of collections, which means we can use these methods to create a list, set, and map.Java Platform Module System (JPMS): A Java Module is a mechanism to bundle java applications and java packages into a Java module. It specifies which of the java packages that contain visible to other java modules by using ... Read More

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