Regex Quantifiers: From Basics to Advanced Techniques | Python in Tamil

Regex quantifiers are symbols or metacharacters that define the quantity or repetition of a preceding element or group in a regular expression. They allow you to specify how many times a particular character, group, or character class should occur in a pattern. Here are some common regex quantifiers: * (asterisk): Matches zero or more occurrences of the preceding element. For example, the pattern a* matches an empty string, "a", "aa", "aaa", and so on. + (plus): Matches one or more occurrences of the preceding element. For example, the pattern a+ matches "a", "aa", "aaa", and so on, but not an empty string. ? (question mark): Matches zero or one occurrence of the preceding element. For example, the pattern colou?r matches both "color" and "colour". {n} (curly braces with a specific number): Matches exactly n occurrences of the preceding element. For example, the pattern a{3} matches "aaa". {n,} (curly braces with a minimum number): Matches at least n occurrences of the preceding element. For example, the pattern a{2,} matches "aa", "aaa", "aaaa", and so on. {n,m} (curly braces with a range): Matches at least n and at most m occurrences of the preceding element. For example, the pattern a{2,4} matches "aa", "aaa", and "aaaa". {n}?, *?, +?, ?? (lazy or non-greedy quantifiers): Performs a non-greedy match of the preceding element. It matches as few occurrences as possible. For example, the pattern a+? matches the smallest possible string that has one or more "a" characters. *, +, ?, {n}, {n,}, {n,m} (greedy quantifiers): These quantifiers are greedy by default, which means they match as many occurrences as possible. For example, the pattern a+ matches the largest possible string that has one or more "a" characters. These quantifiers can be used with any character, character class, or group in a regular expression, allowing you to specify the desired repetition or quantity of the pattern you're trying to match.