A character labeling operation determines the character structure of an input string and writes a label as an output that describes the character structure. To define a character labeling operation, configure a labeler asset in Character mode.
When you configure a character labeling step, you enter a single character as the label. The operation returns the label for each input character that matches the conditions that the step defines.
You can configure a step to compare input characters to the values in a dictionary or to the characters in a character set.
Character labeling with a dictionary
When you configure character labeling with a dictionary, the labeling operation returns a label for each character when an input value matches a dictionary value. The labeling operation returns other characters unchanged in the output.
For example, you might compare the values in a column of surname data with the values in a dictionary of person names. You add N as the label in the character labeling step. The input data and the dictionary both include the name SMITH. The labeling operation returns the string NNNNN as output for the name SMITH. However, the dictionary does not contain the name SMYTH. If the labeling operation finds the name SMYTH in an input string, it writes SMYTH as output.
The labeling operation can recognize a dictionary value within a larger value. For example, the operation can return GOLDNNNNN as the label for the input name GOLDSMITH.
Character labeling with a character set
When you configure character labeling with a character set, the labeling operation returns a label for each character in the input value that matches a character in the character set. The labeling operation returns other characters unchanged in the output.
For example, you might compare the values in a column of Irish postcodes with a character set. Irish post codes have the format A99SAA99, where A is an alphabetic character, 9 is a digit, and S is an optional character space. You define a character set that includes the valid characters and excludes characters such as I,O, and Z that the postcodes do not use.
The labeling operation returns the labels A99SAA99 for the input D08 E1W3, as D08 E1W3 represents a valid postcode format. However, Z08 IO34 does not conform to the format. If the labeling operation finds Z08 IO34 in an input string, it writes Z99SIO99 as output.