R regex to validate user input is correct.

Posted by John on Stack Overflow See other posts from Stack Overflow or by John
Published on 2010-03-16T00:29:14Z Indexed on 2010/03/16 0:29 UTC
Read the original article Hit count: 620

Filed under:

I'm trying to practice writing better code, so I wanted to validate my input sequence with regex to make sure that the first thing I get is a single letter A to H only, and the second is a number 1 to 12 only. I'm new to regex and not sure what the expression should look like. I'm also not sure what type of error R would throw if this is invalidated?

In Perl it would be something like this I think: =~ m/([A-M]?))/)

Here is what I have so far for R:

input_string = "A1"
first_well_row = unlist(strsplit(input_string, ""))[1]  # get the letter out
first_well_col = unlist(strsplit(input_string, ""))[2]  # get the number out

Related posts about regex

Find multiple regex in each line and skip result if one of the regex doesn't match

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a list of variables: variables = ['VariableA', 'VariableB','VariableC'] which I'm going to search for, line by line ifile = open("temp.txt",'r') d = {} match = zeros(len(variables)) for line in ifile: emptyCells=0 for i in range(len(variables)): regex = r'('+variables[i]+r')[:|=|\(](-… >>> More
OWASP Regex Repository: Is this regex correct?

as seen on Stack Overflow - Search for 'Stack Overflow'
I was looking at the regular expression for validating various data types from the (OWASP Regex Repository). One of the regular expressions in there is called safetext and looks like: ^[a-zA-Z0-9\s.\-]+$ My first question is: Is this regular expression correct? complementary question If this… >>> More
Make a Perl-style regex interpreter behave like a basic or extended regex interpreter

as seen on Stack Overflow - Search for 'Stack Overflow'
I am writing a tool to help students learn regular expressions. I will probably be writing it in Java. The idea is this: the student types in a regular expression and the tool shows which parts of a text will get matched by the regex. Simple enough. But I want to support several different regex… >>> More
JS regex isn't matching, even thought it works with a regex tester

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm writing a piece of client-side javascript code that takes a function and finds the derivative of it, however, the regex that's supposed to match with the power rule fails to work in the context of the javascript program, even though it sucessfully matches when it's used with an independent regex… >>> More
c# RegEx with "|"

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to be able to check for a pattern with | in them. For example an expression like d*|*t should return true for a string like "dtest|test". I'm no regex hero so I just tried a couple of things, like: Regex Pattern = new Regex("s*\|*d"); //unable to build because of single backslash Regex Pattern… >>> More

Developer IT

R regex to validate user input is correct. - Developer IT

R regex to validate user input is correct.

r

regex

Related posts about r

Related posts about regex

Find multiple regex in each line and skip result if one of the regex doesn't match

OWASP Regex Repository: Is this regex correct?

Make a Perl-style regex interpreter behave like a basic or extended regex interpreter

JS regex isn't matching, even thought it works with a regex tester

c# RegEx with "|"

Categories cloud