The functions isupper() and islower() in C++ are inbuilt functions present in “ctype.h” header file. It checks whether the given character or string is in uppercase or lowercase.What is isupper()?This function is used to check whether the given string contains any uppercase letter or not and also if we have one character as an input then it checks whether the character is in uppercase or not.Syntaxint isupper ( int arg)ExplanationThis function has return type as int as it returns non zero value when the string contains uppercase letter and 0 otherwise. It has one parameter which will contain the character ... Read More

Given the task is to show the working of deque::cbegin() in C++ STL.What is Deque::cbegin( ) function?deque::cbegin() is a function which comes under deque header file, cbegin() returns the iterator pointer which points to the first element of the deque container.Note − cbegin() function does not have any arguments in it.Syntaxdeq.cbegin();Where deq is the deque’s object.Return ValueThe function returns a const_iterator.const_iterator is a random access iterator which is used to point to the first element of the deque container. We can traverse the whole container using the first element of the container, but this can’t be used to do the ... Read More

Given the task is to show the working of deque::crbegin() in C++.Deque is a double ended queue that gives insertion and deletion at each end i.e. front and back with high performance, in contrast to vector that gives high performance insertion at the end i.e. back only.Also, it provides random access to components too. Though one can insert part in between alternative components in dequeue with insert(), however its performance won't be sensible rather like a vector.What is deque::crbegin()?Deque::crbegin(), where crbegin is the constant reverse begin, implies it constantly reverse the begin or in other words it returns the constant_reverse_iterator.What ... Read More

Except for control characters,  (+ ? . * ^ $ ( ) [ ] { } | \), all characters match themselves. You can escape a control character by preceding it with a backslash.Following table lists the regular expression syntax that is available in Python −Sr.No.Pattern & Description1^Matches beginning of line.2$Matches end of line.3.Matches any single character except newline. Using m option allows it to match newline as well.4[...]Matches any single character in brackets.5[^...]Matches any single character not in brackets6re*Matches 0 or more occurrences of preceding expression.7re+Matches 1 or more occurrence of preceding expression.8re?Matches 0 or 1 occurrence of preceding ... Read More

Regular expression literals may include an optional modifier to control various aspects of matching. The modifiers are specified as an optional flag. You can provide multiple modifiers using exclusive OR (|), as shown previously and may be represented by one of these −Sr.No.Modifier & Description1re.IPerforms case-insensitive matching.2re.LInterprets words according to the current locale. This interpretation affects the alphabetic group (\w and \W), as well as word boundary behavior(\b and \B).3re.MMakes $ match the end of a line (not just the end of the string) and makes ^ match the start of any line (not just the start of the string).4re.SMakes ... Read More

One of the most important re methods that use regular expressions is sub.Syntaxre.sub(pattern, repl, string, max=0)This method replaces all occurrences of the RE pattern in string with repl, substituting all occurrences unless max provided. This method returns modified string.Example Live Demo#!/usr/bin/python import re phone = "2004-959-559 # This is Phone Number" # Delete Python-style comments num = re.sub(r'#.*$', "", phone) print "Phone Num : ", num # Remove anything other than digits num = re.sub(r'\D', "", phone) print "Phone Num : ", numOutputWhen the above code is executed, it produces the following result −Phone Num : 2004-959-559 Phone Num : 2004959559Read More

Python offers two different primitive operations based on regular expressions: match checks for a match only at the beginning of the string, while search checks for a match anywhere in the string (this is what Perl does by default).Example Live Demo#!/usr/bin/python import re line = "Cats are smarter than dogs"; matchObj = re.match( r'dogs', line, re.M|re.I) if matchObj:    print "match --> matchObj.group() : ", matchObj.group() else:    print "No match!!" searchObj = re.search( r'dogs', line, re.M|re.I) if searchObj:    print "search --> searchObj.group() : ", searchObj.group() else:    print "Nothing found!!"OutputWhen the above code is executed, it produces the following ... Read More

This function searches for first occurrence of RE pattern within string with optional flags.SyntaxHere is the syntax for this function −re.search(pattern, string, flags=0)Here is the description of the parameters −Sr.No.Parameter & Description1patternThis is the regular expression to be matched.2stringThis is the string, which would be searched to match the pattern at the beginning of string.3flagsYou can specify different flags using bitwise OR (|). These are modifiers, which are listed in the table below.The re.search function returns a match object on success, none on failure. We use group(num) or groups() function of match object to get matched expression.Sr.No.Match Object Method & Description1group(num=0)This method returns entire match ... Read More

Data hiding is also known as data encapsulation and it is the process of hiding the implementation of specific parts of the application from the user. Data hiding combines members of class thereby restricting direct access to the members of the class. Data hiding plays a major role in making an application secure and more robust Data hiding in Python Data hiding in python is a technique of preventing methods and variables of a class from being accessed directly outside of the class in which the methods and variables are initialized. Data hiding of essential member function prevents the end ... Read More

Suppose you have created a Vector class to represent two-dimensional vectors, what happens when you use the plus operator to add them? Most likely Python will yell at you.You could, however, define the __add__ method in your class to perform vector addition and then the plus operator would behave as per expectation −Example Live Demo#!/usr/bin/python class Vector:    def __init__(self, a, b):       self.a = a       self.b = b    def __str__(self):       return 'Vector (%d, %d)' % (self.a, self.b)    def __add__(self, other):       return Vector(self.a + other.a, self.b + other.b) v1 = ... Read More