Find K-th Smallest Element in a 2D Array Using Python

Arushi
Updated on 30-Jul-2019 22:30:23

493 Views

One n×n user input integer matrix is given and the value of k. Our task is to find out k'th smallest element in a 2D array. Here we use heapq mudule.Heap queue (or heapq) in Python. In Python, it is available using “heapq” module. The technique of this module in python is that each time the smallest of heap element is popped (min heap).nsmallest () method is used to get n least values from a data frame or a series. Example Input Array is:: 10 20 20 40 15 45 40 30 32 33 30 50 ... Read More

Dunder or Magic Methods in Python

karthikeya Boyini
Updated on 30-Jul-2019 22:30:23

666 Views

magic methods that allow us to do some pretty neat tricks in object oriented programming. These methods are identified by a two underscores (__) used as prefix and suffix. As example, function as interceptors that are automatically called when certain conditions are met. In python __repr__ is a built-in function used to compute the "official" string representation of an object, while __str__ is a built-in function that computes the "informal" string representations of an object. Example Code Live Demo class String: # magic method to initiate object def __init__(self, string): ... Read More

MySQL Select Query to Select Rows Not in Another Table

Chandu yadav
Updated on 30-Jul-2019 22:30:23

2K+ Views

For our example, we will create two tables and apply Natural Left Join to get the rows from a table not present in the second table. Creating the first table. mysql> create table FirstTableDemo -> ( -> id int, -> name varchar(100) -> ); Query OK, 0 rows affected (0.48 sec) Inserting records into first table. mysql> insert into FirstTableDemo values(1, 'Bob'), (2, 'John'), (3, 'Carol'); Query OK, 3 rows affected (0.13 sec) Records: 3 Duplicates: 0 Warnings: 0 To display all ... Read More

Difference Between Chash and Visual Chash

Arjun Thakur
Updated on 30-Jul-2019 22:30:23

2K+ Views

C# and Visual C# are both the same. When you use Visual Studio for C# development, it is called Visual C# .Consider Visual C# as an implementation of C#. Microsoft Visual Studio is an IDE from Microsoft to develop programs, web app, web services, etc. The current version of Visual Studio is Visual Studio 2017, that supports .NET 3.5 to 4.7 framework. C# is a multi-paradigm programming language whose current version is C# 7.3. The following reasons make C# a widely used professional language − It is a modern, general-purpose programming language It is object oriented. It is ... Read More

Histograms Equalization Using Python OpenCV Module

Samual Sam
Updated on 30-Jul-2019 22:30:23

716 Views

This is a method in image processing to do contrast adjustment using the image's histogram. Actually this method usually increases the global contrast of many images, especially when the usable data of the image is represented by close contrast values and through this adjustment, the intensities can be better distributed on the histogram and it allows for areas of lower local contrast to gain a higher contrast. OpenCV has a function to do this, cv2.equalizeHist() and its input is just grayscale image and output is our histogram equalized image. This technique is good when histogram of the image is confined ... Read More

Remove All Non-Alphanumeric Characters from a String in MySQL

Chandu yadav
Updated on 30-Jul-2019 22:30:23

2K+ Views

Non-alphanumeric characters are as follows − @, !, #, &, (), ?, / There is no inbuilt function to remove non-alphanumeric characters from a string in MySQL. Therefore, we create a function which removes all non-alphanumeric characters. The function declaration and definition is as follows. mysql> delimiter // mysql> CREATE FUNCTION RemoveNonAlphaNumeric( s CHAR(255) ) RETURNS CHAR(255) DETERMINISTIC -> BEGIN -> DECLARE var1, length SMALLINT DEFAULT 1; -> DECLARE result CHAR(255) DEFAULT ''; -> DECLARE ch CHAR(1); ... Read More

Why Do Integers in Database Row Tuple Have an L Suffix in MySQL

Arjun Thakur
Updated on 30-Jul-2019 22:30:23

310 Views

The ‘L’ suffix concept in MySQL can be related with Python. In Python 2, the long integer literal is suffixed with L or l, but int and long have been binded into int in version 3. Therefore, there is no need for L or l. Adding large numbers in Python Version 3.7 (Python 3), without using any suffix. Here, if we suffix L or l, Python 3 gives an error. However, Python Version 2 suffixed with L or l will not give an error. The following is the output with no error. Hence, Python int is ... Read More

Addition and Blending of Images Using OpenCV in Python

Samual Sam
Updated on 30-Jul-2019 22:30:23

480 Views

We know that when we solve any image related problem, we have to take a matrix. The matrix content will vary depending upon the image type - either it would be a binary image(0, 1), gray scale image(0-255) or RGB image(255 255 255). So if we want to add of two images then that means very simple we have to add respective two matrices. In OpenCV library, we have a function cv2.add() to add the images. But for image addition the size of the two images should be same. Addition of two images import cv2 # Readingour Image1 my_firstpic ... Read More

Find the Number of Columns in a MySQL Table

Ankith Reddy
Updated on 30-Jul-2019 22:30:23

16K+ Views

To find the number of columns in a MySQL table, use the count(*) function with information_schema.columns and the WHERE clause. Let us see an example. Creating a table. mysql> create table NumberOfColumns -> ( -> id int, -> FirstName varchar(100), -> LastName varchar(100), -> Age int, -> Address varchar(100) -> ); Query OK, 0 rows affected (0.70 sec) Inserting records into table. mysql> insert into NumberOfColumns values(1, 'Shane', 'Watson', 36, 'Australia'); Query OK, 1 row affected ... Read More

PHP strip whitespace Function

Chandu yadav
Updated on 30-Jul-2019 22:30:23

123 Views

The php_strip_whitespace() function returns source with stripped comments and whitespace. Syntax php_strip_whitespace(file_path) Parameters file_path − The path of file. Return The php_strip_whitespace() function returns stripped source code on success. Example The above code strip all the comments and whitespace.

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