One of the most common operations carried out on string data is extracting parts of a string. This
is especially prevalent during the early data-cleaning phase of a data project.
There are two common string extraction scenarios which we will cover here:
Extract by Location: Extract a
substring given its start location and length. For instance; extract the second through to
the tenth characters of a string.
Extract by Regular Expression:
Extract a substring that matches a given regular expression. For instance; extract the first
occurrence of a sequence of digits from a string. Substring extraction by regular expressions is
quite powerful and is by far the most common method of string extraction in practice.