Indentation is an important feature of Python syntax. Code blocks in function, class or loops are required to follow same indent level for statements in it. The tabnanny module in Python's standard library is able to detect any violation in this stipulation.This module is primarily intended to be used in command line mode with –m switch. However, it can also be imported in an interpreter session.Command line usagepython –m tabnanny –q example.pyFor verbose output use –v switchpython –m tabnanny –v example.pyFollowing functions are defined in tabnanny module for checking indentation programmatically.check()This function checks for ambiguously indented lines in a given ... Read More

The name can be validated using the java.util.regex.Pattern.matches() method. This method matches the regular expression for the name and the given input name and returns true if they match and false otherwise.A program that demonstrates this is given as follows:Example Live Demopublic class Demo {    public static void main(String args[]) {       String name = "John Harry Smith";       String regexName = "\p{Upper}(\p{Lower}+\s?)";       String patternName = "(" + regexName + "){2, 3}";       System.out.println("The name is: " + name);       System.out.println("Is the above name valid? " + name.matches(patternName));   ... Read More

The specified string can be split around a particular match for a regex using the String.split() method. This method has a single parameter i.e. regex and it returns the string array obtained by splitting the input string around a particular match for the regex.A program that demonstrates splitting a string is given as follows:Example Live Demopublic class Demo {    public static void main(String args[]) {       String regex = "_";       String strInput = "The_sky_is_blue";       System.out.println("Regex: " + regex);       System.out.println("Input string: " + strInput);       String[] strArr = ... Read More

The specified input sequence can be split around a particular match for a pattern using the java.util.regex.Pattern.split() method. This method has a single parameter i.e. the input sequence to split and it returns the string array obtained by splitting the input sequence around a particular match for a pattern.A program that demonstrates the method Pattern.split() in Java regular expressions is given as follows:Example Live Demoimport java.util.regex.Pattern; public class Demo {    public static void main(String[] args) {       String regex = "_";       String input = "Oranges_are_orange";       System.out.println("Regex: " + regex);       ... Read More

The Email address can be validated using the java.util.regex.Pattern.matches() method. This method matches the regular expression for the E-mail and the given input Email and returns true if they match and false otherwise.A program that demonstrates this is given as follows:Example Live Demopublic class Demo {    static boolean isValid(String email) {       String regex = "^[\w-_\.+]*[\w-_\.]\@([\w]+\.)+[\w]+[\w]$";       return email.matches(regex);    }    public static void main(String[] args) {       String email = "john123@gmail.com";       System.out.println("The E-mail ID is: " + email);       System.out.println("Is the above E-mail ID valid? " + ... Read More

The java.util.regex.Pattern.matches() method matches the regular expression and the given input. It has two parameters i.e. the regex and the input. It returns true if the regex and the input match and false otherwise.A program that demonstrates the method Pattern.matches() in Java regular expressions is given as follows:Example Live Demoimport java.util.regex.Pattern; public class Demo {    public static void main(String args[]) {       String regex = "a*b";       String input = "aaab";       System.out.println("Regex: " + regex);       System.out.println("Input: " + input);       boolean match = Pattern.matches(regex, input);       ... Read More

The Matcher can be reset using the java.util.regex.Matcher.reset() method. This method returns the reset Matcher.A program that demonstrates the method Matcher.reset() in Java regular expressions is given as follows:Example Live Demoimport java.util.regex.Matcher; import java.util.regex.Pattern; public class MainClass {    public static void main(String args[]) {       Pattern p = Pattern.compile("(a*b)");       Matcher m = p.matcher("caaabcccab");       System.out.println("The input string is: caaabcccab");       System.out.println("The Regex is: (a*b)");       System.out.println();       while (m.find()) {          System.out.println(m.group());       }       m.reset();       System.out.println("The ... Read More

The find() method finds the subsequence in an input sequence that matches the pattern required. This method is available in the Matcher class that is available in the java.util.regex package.A program that demonstrates the method Matcher.find() in Java regular expressions is given as follows:Example Live Demoimport java.util.regex.Matcher; import java.util.regex.Pattern; public class Demo {    public static void main(String args[]) {       Pattern p = Pattern.compile("Sun");       Matcher m = p.matcher("The Earth revolves around the Sun");       System.out.println("Subsequence: Sun");       System.out.println("Sequence: The Earth revolves around the Sun");       if (m.find())     ... Read More

The offset value after the last character is matched from the sequence according to the regex is returned by the method java.util.regex.Matcher.end(). This method requires no arguments. If no match occurs or if the match operation fails then the IllegalStateException is thrown.A program that demonstrates the method Matcher.end() Java regular expressions is given as follows:Example Live Demoimport java.util.regex.Matcher; import java.util.regex.Pattern; public class Demo {    public static void main(String args[]) {       Pattern p = Pattern.compile("(a*b)");       Matcher m = p.matcher("caaabccaab");       System.out.println("The input string is: caaabccaab");       System.out.println("The Regex is: (a*b)");   ... Read More

A character class is set of characters that are enclosed inside square brackets. The characters in a character class specify the characters that can match with a character in an input string for success. An example of a character class is [a-z] which denotes the alphabets a to z.A program that demonstrates a character class in Java Regular Expressions is given as follows:Example Live Demoimport java.util.regex.Matcher; import java.util.regex.Pattern; public class Demo {    public static void main(String args[]) {       Pattern p = Pattern.compile("[a-z]+");       Matcher m = p.matcher("the sky is blue");       System.out.println("The input ... Read More