Regex Search and Match¶
Searches an input string using a regular expression and returns all matches as a list. It supports multiline text input and standard regular expression syntax. Results reflect Python-style regex behavior, including how capture groups affect output.
Usage¶
Use this node to extract patterns from text, such as emails, IDs, words of a certain length, or any custom pattern. Typically placed after a node that provides text content and before downstream nodes that iterate over or analyze the extracted matches.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| text_input | True | STRING | The text to search for matches. Supports multiline input. | Please contact us at support@example.com or sales@example.org. |
| regex_pattern | True | STRING | Regular expression pattern to find matches. Uses Python regex syntax. You can use inline flags like (?i) for case-insensitive matches. | \b[a-zA-Z]{6}\b |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| matches | LIST | List of all matches found in the input text. If the pattern contains capture groups, each match may be a string (no groups) or a tuple (one or more groups). Returns an empty list if no matches are found. | ['support', 'sales'] |
Important Notes¶
- Regex behavior: Matches are computed with Python's re.findall. If your pattern contains capture groups, the output elements may be tuples rather than plain strings.
- No explicit flags input: Inline flags like (?i), (?m), (?s) can be embedded in the pattern to control case sensitivity, multiline, and dotall behavior.
- Escaping: Remember to escape backslashes in patterns (e.g., use "\b" for a word boundary).
- Empty results: If no matches are found, the node outputs an empty list.
- Invalid patterns: A malformed regex pattern will cause an error; validate your pattern before running.
Troubleshooting¶
- Unexpected empty list: Verify the pattern matches your text and consider case sensitivity. Add inline flags like (?i) if needed.
- Matches are tuples instead of strings: Your pattern contains capture groups. Use non-capturing groups (?:...) or adjust downstream logic.
- Regex compilation error: The pattern is invalid. Test and correct the pattern (e.g., unbalanced brackets or parentheses).
- Greedy vs. non-greedy matches: If matches are larger than expected, use non-greedy quantifiers like *? or +?.
- Escaping issues: Double-escape backslashes in the pattern string (e.g., "\d+" for digits).
Example Pipelines¶
