Master Python Regex: 14 Essential Special Characters Explained

Today we share the last special character of regular expressions, \d, with a tutorial.

The special character \d represents a digit.

To match the specific string 2004 , add the non‑greedy quantifier ? . This switches to non‑greedy mode, matching the shortest possible sequence and producing 2004 as output.

Curly braces specify the exact length of a numeric match. For example, {4} matches exactly four consecutive digits.

The article then reviews fourteen common regex symbols:

^ anchors the match to the start of a string.

* allows the preceding element to appear zero or more times.

. matches any single character.

$ anchors the match to the end of a string.

? makes the preceding quantifier non‑greedy.

+ requires the preceding element to appear one or more times.

{2} , {2,} , {2,5} specify exact, minimum, or range repetitions respectively.

| acts as a logical OR between alternatives.

[] , [A-Za-z0-9] , [^] define character classes, ranges, and negations.

\s matches whitespace, while \S matches non‑whitespace.

\w matches alphanumeric characters and underscore (equivalent to [A-Za-z0-9_] ); \W matches any character not in that set.

[\u4E00-\u9FA5] matches Chinese characters.

() creates capturing groups for extracting substrings.

\d matches digits (0‑9).

Each symbol is illustrated with example images throughout the article.