This node splits the string content of a selected column into logical groups using regular expressions. A group is identified by a pair of parentheses, whereby the pattern in such parentheses is a regular expression. Each content of each group is appended as an individual column. All appended columns will contain missing values if the input string is not completely matched by the selected regular expression.
A short introduction to Groups and Capturing is given by in the Java API . Some examples are given below:
Patent identifiers such as "US5443036-X21" consisting of
a (at most) two letter country code ("US"), a patent
number ("5443036") and possibly some application code
("X21"), which is separated by a dash or a space
character, can be grouped by the expression
Each of the parenthesized terms corresponds to the
This is particularly useful when this node is used to
parse the file URL of a file reader node (the URL is
exposed as flow variable and then exported to a table
using a Variable to Table node). The format of such
URLs is similar to "file:c:\some\directory\foo.csv".
Using the pattern
generates four groups (by counting the number of opening
parentheses): The first group identifies the directory
and is denoted by "(.*[/\\])". It consumes all characters
until a final slash or backslash is encountered; in the example
this refers to "c:\some\directory\". The second group
represents the file name, whereby it encapsulates the
third and fourth group. The third group (denoted by
"([^\.]*)") consumes all characters after the directory,
which are not a dot '.' (which is "foo" in the
above example). The pattern expects a single dot
(which is ignored) and finally the fourth group "(.*$)",
which reads until the end of the string and indicates
the file suffix ('csv'). The groups for the above
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