Write a regular expression[both search and replace patterns] to split the values, such that the column has only names and ID's like Column A: Hotel and Column B: 1234
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Answer:
1. Regular Expression Tutorial
In this tutorial, I will teach you all you need to know to be able to craft powerful time-saving regular
expressions. I will start with the most basic concepts, so that you can follow this tutorial even if you know
nothing at all about regular expressions yet.
But I will not stop there. I will also explain how a regular expression engine works on the inside, and alert you
at the consequences. This will help you to understand quickly why a particular regex does not do what you
initially expected. It will save you lots of guesswork and head scratching when you need to write more
complex regexes.
What Regular Expressions Are Exactly - Terminology
Basically, a regular expression is a pattern describing a certain amount of text. Their name comes from the
mathematical theory on which they are based. But we will not dig into that. Since most people including
myself are lazy to type, you will usually find the name abbreviated to regex or regexp. I prefer regex, because
it is easy to pronounce the plural “regexes”. In this book, regular expressions are printed between guillemots:
«regex». They clearly separate the pattern from the surrounding text and punctuation.
This first example is actually a perfectly valid regex. It is the most basic pattern, simply matching the literal
text „regex”. A "match" is the piece of text, or sequence of bytes or characters that pattern was found to
correspond to by the regex processing software. Matches are indicated by double quotation marks, with the
left one at the base of the line.
«\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b» is a more complex pattern. It describes a series of
letters, digits, dots, underscores, percentage signs and hyphens, followed by an at sign, followed by another
series of letters, digits and hyphens, finally followed by a single dot and between two and four letters. In other
words: this pattern describes an email address.
With the above regular expression pattern, you can search through a text file to find email addresses, or verify
if a given string looks like an email address. In this tutorial, I will use the term “string” to indicate the text that
I am applying the regular expression to. I will indicate strings using regular double quotes. The term “string”
or “character string” is used by programmers to indicate a sequence of characters. In practice, you can use
regular expressions with whatever data you can access using the application or programming language you are
working with.