How to use regular expression in Scala spark?
Closed 3 years ago. I’m having trouble using regular expression. My sample data is: found: scala.util.matching.Regex required: String val b = a.filter (line => !line.startsWith (pattern)) ^ Actually, I’m not sure how exactly to use regex in Spark . Please help.
Table of Contents
How to find regular expression patterns in Scala strings?
This is Recipe 1.7, “Finding patterns in Scala strings”. You must determine whether a Scala String contains a regular expression pattern. Create a Regex object by calling the .r method on a string, and then use that pattern with findFirstIn when finding a match and findAllIn when finding all matches.
How to search for a string in Scala?
To demonstrate this, first create a Regex for the pattern you want to search for, in this case a sequence of one or more numeric characters: scala> val match1 = numPattern.findFirstIn(address) match1: Option [String] = Some (123 ) (Notice that this method returns an Option [Cadena]. I’ll go deeper into that in the Discussion.)
How can I use Spark to match strings?
The Spark rlike method allows you to write powerful string-matching algorithms with regular expressions (regexp). This blog post will describe tactics for detecting strings that match multiple different patterns and how to abstract these patterns from regular expressions in CSV files.
How to pass a function as an argument in Scala?
As you can see, the timeFlies function has been removed and replaced with the anonymous function code in the main method. As a final example of passing a function as an argument to another Scala function, the following example shows how several different functions are passed to a function called sum().
What does a lambda expression mean in Scala?
Lambda expression in Scala. Lambda Expression refers to an expression that uses an anonymous function instead of a variable or value.
How to convert a string array to a string column in spark?
In this Spark article, I’ll explain how to convert an array of String columns in a DataFrame to a String column (separated or concatenated with a comma, space, or any delimiter character) using the Spark function concat_ws() (translates to concat with separator) , map() transformation and with SQL expression using the Scala example.