Find and replace values in your column using the replace transform. You can find the value to replace by matching the value using different options available and replace it with your input.
To find and replace column data
1. Right-click the column name and select Replace from the context menu.
2. DataPrep offers several advanced matching options to make it easier to find a value from your column data. The options available under Replace options are:
3. Based on the selected option, provide your input to find the value and provide the value which should replace what is found.
Let's take a look at the inputs required for some of the options listed above.
Start and end index:
Start index - Replace the value starting from the start index. The default start index is 1.
End index - The index value up to which the value will be replaced.
Start index and length:
Start index - Replace the value starting from the start index. The default start index is 1.
Length - Replace the value from the start index to the given length.
Matching text or pattern:
Text or pattern to match - Replace the value that matches with the given text or pattern.
Starting text or pattern - Replace the value starting from the given text or pattern.
Ending text or pattern - Replace the value ending before the given text or pattern.
Note : If you are not familiar with pattern matching in DataPrep, read about it here .
Regex:
Regex pattern - Enter the regex of the value which you want to replace.
First 'n' characters:
Number of characters to replace - Specify the number of characters to replace from the start of the value.
Last 'n' characters:
Number of characters to replace - Specify the number of characters to replace from the end of the value.
Replace with:
The value you want to replace the matched text or pattern with.
4. You can also choose to Ignore case or Replace all if required.
To apply filters
If you want to apply some filters along with this transform, you can use the filters functionality.
1. Click the Filters tab.
2. Click the
icon and add the required columns in the
Filters section. You can also reorder the filters using the drag and drop method.
3. For every column added, you can select one of the following options from the drop-down:
- Actual: This option lets you filter rows based on the actual values in the column. Click here to know more.
- Data quality: This option lets you filter rows based on the quality of data in the column. Click here to know more.
- Patterns: This option helps you filter rows based on the data patterns in the selected column. Click here to know more.
- Seasonal: This option helps you filter rows based on the seasonal parameters such as quarter, month, week, etc. Click here to know more.
- Outliers: This option allows you to filter rows based on the outliers present in the data of the selected column. Click here to know more.
Note: The filter options are displayed based on the datatype of the column added for the filter.
4. When you add more than one filter to the Filters section, the logical operators, AND or OR appear next to the filters. You can click to toggle the logical operator between AND and OR.
- Using the logical operators, you can combine the conditions and apply logic to determine the rule of precedence. The final expression is displayed in the Criteria expression box. You can click Edit to alter the default expression using logical operators and parenthesis to specify the precedence or the sequential order as to which condition should be evaluated first. Click Save after making the required changes.
- For example, In the expression, ((1 OR 2) AND (3 OR 4)) , at first the condition ( 1 OR 2 ) will be executed and the condition ( 3 OR 4 ) will be executed next. Thirdly, since, the AND operator is used, the filter will be applied when both the conditions are true.
5. You can further drill down to choose specific values based on the filter option selected for each filter, in the next section.
For example, in the above screenshot, the Data quality option is selected for the All columns filter in the Filters section. Based on the selection, further options to filter specific values are displayed in the All columns (Data quality) section.
6. You can choose to include or exclude the selected items in the last section.
7. If you want to remove all the filters for some reason, you can use the Clear button.
8. A live preview of the filter transform is shown as you make changes.
9. Click the Apply button to apply the transform along with the filters.