How do I select a substring using a regexp in robot framework

Question

In the Robot Framework library called String, there are several keywords that allow us to use a regexp to manipulate a string, but these manipulations don't seem to include selecting a substring from a string.

To clarify, what I intend is to have a price, i.e. € 1234,00 from which I would like to select only the 4 primary digits, meaning I am left with 1234 (which I will convert to an int for use in validation calculations). I have a regexp which will allow me to do that, which is as follows:

(\d+)[\.\,]

If I use Remove String Using Regexp with this regexp I will be left with exactly what I tried to remove. If I use Get Lines Matching Regexp, I will get the entire line rather than just the result I wanted, and if I use Get Regexp Matches I will get the right result except it will be in a list, which I will then have to manipulate again so that doesn't seem optimal.

Did I simply miss the keyword that will allow me to do this or am I forced to write my own custom keyword that will let me do this? I am slightly amazed that this functionality doesn't seem to be available, as this is the first use case I would think of when I think of using a regexp with a string...

Answer 1

You can use the Evaluate keyword to run some python code.

For example:

| Using 'Evaluate' to find a pattern in a string
| | ${string}= | set variable | € 1234,00
| | ${result}= | evaluate | re.search(r'\\d+', '''${string}''').group(0) | re
| | should be equal as strings | ${result} | 1234

Starting with robot framework 2.9 there is a keyword named Get regexp matches, which returns a list of all matches.

For example:

| Using 'Get regexp matches' to find a pattern in a string
| | ${string}= | set variable | € 1234,00
| | ${matches}= | get regexp matches | ${string} | \\d+
| | should be equal as strings | ${matches[0]} | 1234