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While a superclass method throws an exception while overriding it you need to follow the certain rules.The sub class method Should throw Same exception or, sub type −It should not throw an exception of super type −You may leave the method in sub class Without throwing any exceptionAccording to the 3rd rule, if the super-class method throws certain exception, you can override it without throwing any exception.ExampleIn the following example the sampleMethod() method of the super-class throws FileNotFoundException exception and, the sampleMethod() method does not throw any exception at all. Still this program gets compiled and executed without any errors.import ... Read More
From Java 1.5 Scanner class was introduced. This class accepts a File, InputStream, Path and, String objects, reads all the primitive data types and Strings (from the given source) token by token using regular expressions.To read various datatypes from the source using the nextXXX() methods provided by this class namely, nextInt(), nextShort(), nextFloat(), nextLong(), nextBigDecimal(), nextBigInteger(), nextLong(), nextShort(), nextDouble(), nextByte(), nextFloat(), next().Whenever you take inputs from the user using a Scanner class. If the inputs passed doesn’t match the method or an InputMisMatchException is thrown. For example, if you reading an integer data using the nextInt() method and the value ... Read More
Since Java 7 try-with resources was introduced. In this we declare one or more resources in the try block and these will be closed automatically after the use. (at the end of the try block)The resources we declare in the try block should extend the java.lang.AutoCloseable class.ExampleFollowing program demonstrates the try-with-resources in Java.import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; public class FileCopying { public static void main(String[] args) { try(FileInputStream inS = new FileInputStream(new File("E:\Test\sample.txt")); FileOutputStream outS = new FileOutputStream(new File("E:\Test\duplicate.txt"))){ byte[] buffer = new byte[1024]; ... Read More
In Java you can declare three types of variables namely, instance variables, static variables and, local variables.Local variables − Variables defined inside methods, constructors or blocks are called local variables. The variable will be declared and initialized within the method and the variable will be destroyed when the method has completed.Class (static) variables − Class variables are variables declared within a class, outside any method, with the static keyword.Static methods in try-blockIn the same way, static variables belong to the class and can be accessed anywhere within the class, which contradicts with the definition of the local variable. Therefore, declaring ... Read More
Mean, Median and Mode are very frequently used statistical functions in data analysis. Though there are some python libraries.Finding MeanMean of a list of numbers is also called average of the numbers. It is found by taking the sum of all the numbers and dividing it with the count of numbers. In the below example we apply the sum() function to get the sum of the numbers and th elen() function to get the count of numbers.Examplenum_list = [21, 11, 19, 3, 11, 5] # FInd sum of the numbers num_sum = sum(num_list) #divide the sum with length of the ... Read More
If there is a need to find 10 most frequent words in a data set, python can help us find it using the collections module. The collections module has a counter class which gives the count of the words after we supply a list of words to it. We also use the most_common method to find out the number of such words as needed by the program input.ExamplesIn the below example we take a paragraph, and then first create a list of words applying split(). We will then apply the counter() to find the count of all the words. Finally ... Read More
Extracting only the numbers from a text is a very common requirement in python data analytics. It is done easily using the python regular expression library. This library helps us define the patterns for digits which can be extracted as substrings.ExamplesIn the below example we use the function findall() from the re module. The parameters to these function are the pattern which we want to extract and the string from which we want to extract. Please note with below example we get only the digits and not the decimal points or the negative signs.import re str=input("Enter a String with numbers: ... Read More
In this article, we will learn about Logic Gates in Python. Let’s look at each of the logic gates in Python in detail with some easy examples.All of us are quite familiar while implementing logic gates in the processing of electrical signals and are widely used in the electrical and electronics industry. They are used in the diodes and transistors so that we can design by proper alignment of these electronic devices. In this article we will learn about the implementation of some basic gates ‘and‘, ‘or‘ ,’not‘ , ‘nand‘ ,’nor‘ in Python 3.x or earlier.These gates can be implemented ... Read More
In this article, we will learn about a program in which we can remove an all characters other than alphabets using the concept of list comprehension and ord() function in Python 3.x. Or earlier.Algorithm1.We Traverse the given string to check the charater. 2.Selection of characters is done which lie in the range of either [a-z] or [A-Z]. 3.Using the join function we print all the characters which pass the test together.Exampledef remchar(input): # checking uppercase and lowercase characters final = [ch for ch in input if (ord(ch) in range(ord('a'), ord('z')+1, 1)) or (ord(ch) in range(ord('A'), ord('Z')+1, 1))] return ... Read More
As python allows duplicate elements in a list we can have one element present multiple Times. The frequency of elements in a list indicates how many times an element occurs in a list. In this article we use the Counter function of the collections module to find out the frequency of each item in a list.SyntaxSyntax: Counter(list) Where list is an iterable in pythonExampleThe below code uses the Counter() to keep track of frequency and items() to iterate over each item in the result of counter function for printing in a formatted manner.from collections import Counter list = ['Mon', 'Tue', ... Read More