Programming Articles - Page 2089 of 3363

By adding strings in python we just concatenate them to get a new string. This is useful in many scenarios like text analytics etc. Below are the two approaches we consider for this task.Using += OperatorThe + operator can be used for strings in a similar was as it is for numbers. The only difference being, in case of strings the concatenation happens and not a numeric addition.Example Live Demos1 = "What a beautiful " s2 = "flower " print("Given string s1 : " + str(s1)) print("Given string s2 : " + str(s2)) #Using += operator res1 = s1+s2 print("result ... Read More

We may sometimes need to append zeros as string to various data elements in python. There may the reason for formatting and nice representation or there may be the reason for some calculations where these values will act as input. Below are the methods which we will use for this purpose.Using format()Here we take a DataFrame and apply the format function to the column wher we need to append the zeros as strings. The lambda method is used to apply the function repeatedly.Exampleimport pandas as pd string = {'Column' : ['HOPE', 'FOR', 'THE', 'BEST']} dataframe=pd.DataFrame(string) print("given column is ") print(dataframe) ... Read More

Lists can be nested. Which means we have smaller lists as elements inside a bigger list. In this article we solve the challenge of adding the elements of a simple list to the elements of a nested list. If the length of the lists are different then the length of the smaller list becomes the maximum length of the resulting list.Below are the various methods to accomplish this.Using for LoopIn this method, we take the length of the smaller list and loop through the elements of this list adding it to the elements of the bigger list. Here we use ... Read More

Tkinter, which is the GUI library for python programming has a feature to add images to the GUI buttons. This is useful for users to remember the symbols in the GUI rather than the text in the GUI. In the below Tkinter program we show how we can add an image to a GUI button. The photoimage method from the imageKT module is used. We mention the local path to the image file.Examplefrom tkinter import * from PIL import ImageTk ,Image base = Tk() base.title('Start Button') img=ImageTk.PhotoImage(Image.open ("D:\button.jpg")) lab=Label(image=img) lab.pack() button=Button(base, text='exit', command=base.quit) button.pack() base.mainloop()OutputRunning the above ... Read More

Java 9 provides factory methods to create immutable lists, sets, and maps. It can be useful to create empty or non-empty collection objects. In Java 8 and earlier versions, we can use collection class utility methods like unmodifiableXXX to create immutable collection objects. If we need to create an immutable list, then use the Collections.unmodifiableList() method. What does Immutable mean? An object is considered immutable if its state cannot change after it is constructed. Any modification creates a new object instead. String name = "TutorialsPoint"; name = name + "10"; Here, "TutorialsPoint" is an immutable string, and we cannot modify it directly. Instead, we use the ... Read More

In this article, we will learn about useful commands in JShell. Java 9 has introduced a new interactive tool called JShell. This tool can be used to execute, test user-friendly and easy way of Java classes, interfaces, enums, objects, statements and etc.  Different Useful Commands in JShell Below are some of the important commands in JShell: /open /var /types /methods /list /help /open To execute a script after JShell has started, we will use ... Read More

JShell is a new java shell tool released in java 9. It is the first official REPL (Read-Evaluate-Print-Loop) application. This tool helps in executing and evaluating simple java programs and logics such as statements, loops, expressions, and etc. Java REPL provides a simple programming environment in the command prompt. It can read the input, evaluate it and print the output.In the below example we can able to create a class and object in JShell using command prompt.Examplejshell> class Employee { ...> private String name; ...>    Employee(String name) { ...>       this.name=name; ...> } ...> ... Read More

StackWalker API allows easy filtering and lazy access to execute tasks within any method. It is an efficient API for obtaining stack trace information in Java 9.There are three new important classes in StackWalker API: StackWalker,  StackWalker.StackFrame and StackWalker.Option.StackWalker − It is the main class in StackWalker API. We traverse stack frames by using StackWalker.forEach() method and get caller class in an efficient way by calling StackWalker.getCallerClass() method. We walk through stack traces and applying a function on a stream of stack frames by using StackWalker.walk() method.StackWalker.StackFrame − It is a static nested class of StackWalker and represents method invocation return by StackWalker. It has methods ... Read More

In this tutorial, we will be discussing a program to find the number of sub-sequences having product k) {       discard_count += power(2, n - i);       return;    }    if (i == n)       return;       float rem = prefix[n - 1] - prefix[i];    if (sum + a[i] + rem > k)       solve(i + 1, n, sum + a[i], k, a, prefix);    if (sum + rem > k)       solve(i + 1, n, sum, k, a, prefix); } int countSubsequences(const int* arr, ... Read More

In this tutorial, we will be discussing a program to find the number of walks from a source to a destination with exactly k edges.For this we will be provided with a graph and the values of source and destination. Our task is to find all the possible paths starting from the source to the destination having exactly k edges.Example Live Demo#include using namespace std; #define V 4 //counting walks using recursion int countwalks(int graph[][V], int u, int v, int k){    if (k == 0 && u == v)       return 1;    if (k == 1 && graph[u][v])       return 1;    if (k