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Extract Text

The Extract Text task allows for partial extraction of values from a text column. In other words, you can extract sub-strings from text values.

Quickstart​

Let us start with the following sample data:

URL
website1.com/Alice
website2.com/Bob
website1.com/Chuck

Let us assume that you want to extract the name in the column URL. That is everything following the string /. Complete the following steps to achieve this.

  1. Go to Transform > Text Functions.
  2. Select the Extract Text function.
  3. Choose the column URL as the column to extract text from.
  4. Select Characters around a LETTER/WORD for the What to Extract option.
  5. Select All characters right of letter/word.
  6. Enter '/' in the input box for letter/word.
  7. Apply result into a new column called Name.
  8. Click APPLY.

The resulting data appears as shown below.

URLName
website1.com/AliceAlice
website2.com/BobBob
website1.com/ChuckChuck

Supported Options​

The following options are supported by this task:

  • Extract Text From: The column to extract sub-string from.
  • What to Extract: This option allows you to choose from one of the following three options:
  1. Characters at a certain position
  2. Characters around a letter/word
  3. Characters from beginning or end
  4. Starts with
  5. Does not start with
  6. Ends with
  7. Does not end with
  8. Starts with a number
  9. Does not start with a number
  10. Ends with a number
  11. Does not end with a number
  12. Contains a number
  13. Does not contain a number
  14. Regular expression
  15. All except regular expression
  • Parameters: Set of options that allow specification of other inputs as required by the choice of What to extract option. For more information, see:
  • Conditions: See how to apply conditions.
  • Apply result into: This option allows configuration of the destination of the results by this task. See result documentation.

Extraction Types​

Mammoth supports the following sub-string extraction techniques. Each of these techniques can be used to achieve multiple sub-objectives and they are controlled using the parameters in the options that follow the What to Extract section.

Extracting characters from a certain position​

By using this option, you can achieve one of the following objectives:

  1. Extract all characters to the left of a specific position.
  2. Extract all characters to the right of a specific position.
  3. Extract specific number of characters to the left of a specific position.
  4. Extract specific number of characters to the right of a specific position.

Extracting characters around a letter/word​

By using this option, you can achieve one of the following objectives:

  1. Extract all characters to the left of a letter/word.
  2. Extract all characters to the right of a letter/word.
  3. Extract specific number of characters to the left of a letter/word.
  4. Extract specific number of characters to the right of a letter/word.

The letter/word can be included in the extracted string by using the left of and including/right of and including option.

Extracting characters from beginning or end​

By using this option, one of the following objectives can be achieved.

  1. Extract a specific number of characters from the beginning of the string.
  2. Extract a specific number of characters from the end of the string.

Starts with​

You can use this option to extract all strings that starts with a specific word/number/character.

Does not start with​

You can use this option to extract all strings that does NOT start with a specific word/number/character.

Ends with​

You can use this option to extract all strings that ends with a specific word/number/character.

Does not end with​

You can use this option to extract all strings that does NOT end with a specific word/number/character.

Starts with a number​

You can use this option to extract all strings that starts with a number.

Does not start with a number​

You can use this option to extract all strings that does NOT start with a number.

Ends with a number​

You can use this option to extract all strings that ends with a number.

Does not end with a number​

You can use this option to extract all strings that does NOT end with a number.

Contains a number​

You can use this option to extract all strings that contains a number.

Does not contain a number​

You can use this option to extract all strings that does NOT contain a number.

Regular expression​

You can use Regular expression, or RegEx, to customize a search pattern. It's a powerful tool to find and extract sub-strings from a text column that would otherwise not match any other pre-defined searches above.

Refer to this Regex documentation for detailed information on usage.

All except regular expression​

Use All except regular expression when you want to remove the specified regex string from the extract.

This is how:

  • Open the tasks menu → “Text Functions” → “Extract Text”
  • In the "What to extract" drop down, select “All except regular expression”
  • Enter the RegEx in the field below it. It should look something like this:
  • Click Apply and it'll extract everything except the regex.

Refer to this guide to learn how to create regular expressions.

info
  1. Result Column: The result column documentation
  2. Conditions: To apply conditions to extraction.