Create regular expressions as easy as a breeze. This node allows you to build, preview, and test your regexes in real time with your real data. Say good bye to creating your regex in KNIME with trial and error, or copying back and forth regular expressions and text between your favorite regex tool and KNIME. The user interface is inspired by RegExr and Regular Expressions 101.
The node uses Java’s Pattern
implementation. For each row or text input, it will extract all
matches. Each capturing group is automatically mapped to a KNIME
column. To define the column names, you can make use of
“named capturing groups”, such as
(?<name>[A-Z-a-z]+).
To exclude groups from the output, define them as “non-capturing group”: (?:).
Usage Example: Extract email addresses from text
For this input text: “Hello, world! mail@palladian.ai The
quick brown fox jumps over the lazy dog. bob@example.com Lorem
ipsum.” and the
\b(?<Local Part>[A-Z0-9._%+-]+)@(?<Domain>[A-Z0-9.-]+\.[A-Z]{2,})\b,
the node will create a KNIME table as follows:
| Full Match | Local Part | Domain |
|---|---|---|
| mail@palladian.ai | palladian.ai | |
| bob@example.com | bob | example.com |
Standalone Mode
The node can be used with an input table, which provides a string column, or in “standalone” mode (when no input table is connected), where you can enter the text into the node dialog.
Further reading
For a general introduction into regular expressions, have a look at Regular-Expressions.info.
Options
Popular Successors
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Column Rename2 %- Column Rename (Regex)2 %
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- Column Filter (legacy)< 1 %
- Table View (JavaScript)< 1 %
- Table to JSON< 1 %
- GET Request< 1 %
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- Date&Time to String< 1 %
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Recursive Loop Start< 1 %- Math Formula (Multi Column)< 1 %
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CSV Writer< 1 %- Table Writer< 1 %
Recursive Loop Start (2 ports)< 1 %- Case Converter< 1 %
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Variable to Table Column< 1 %Table Column to Variable< 1 %- Read Images< 1 %
Counting Loop Start< 1 %- Interval Loop Start< 1 %
- Recursive Loop Start< 1 %
- Column Comparator< 1 %
Column Appender< 1 %- Table Validator< 1 %
- Missing Value Column Filter< 1 %
- Row Splitter (Labs)< 1 %
- Rank< 1 %
String Replace (Dictionary)< 1 %- Table Difference Finder< 1 %
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DB Table Creator< 1 %- One Row to Many< 1 %
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- Math Formula (Variable)< 1 %
Excel Writer (XLS)< 1 %- Java Snippet (simple)< 1 %
- Case Converter< 1 %
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Workflows
20220503_filter_rows_stopwordsKNIME Forum- 24245-1-1KNIME Forum
- 31501_regex_matcherKNIME Hub
- 31892-struggling-to-split-cellKNIME Hub
- Add filename to column headersKNIME Hub
- Show all 82 workflows
Links
- Ka-Boom! Palladian 2.0by qqilihq on 2020-01-27forum.knime.com/p/79848
- String Manipulation Regex?by qqilihq on 2020-02-18forum.knime.com/p/81851
- Pattern sequence string recognition and extractionby armingrudd on 2020-05-30forum.knime.com/p/92921
- Extract first number from stringby armingrudd on 2020-01-28forum.knime.com/p/79975
- Regular expression helpby qqilihq on 2020-04-09forum.knime.com/p/86981
- Show all 48 links
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