To search for and match patterns in text and other data, regular expressions are an indispensable tool for the data scientist. Julia adheres to the Perl syntax of regular expressions. For a complete reference, refer to http://www.regular-expressions.info/reference.html. Regular expressions are represented in Julia as a double (or triple) quoted string preceded by r
, such as r"..."
(optionally, followed by one or more of the i
, s
, m
, or x
flags), and they are of type Regex
. The chapter 2\regexp.jl
script shows some examples.
In the first example, we will match the e-mail addresses (#>
shows the result):
email_pattern = r".+@.+" input = "[email protected]" println(ismatch(email_pattern, input)) #> true
The regular expression pattern +
matches any (non-empty) group of characters. Thus, this pattern matches any string that contains @
somewhere in the middle.
In the second example, we will try to determine whether a credit card number is valid or not:
visa = r"^(?:4[0-9]...