field-calculatorqgis
The strpos() function searches from the left side of the string. But instead of always trimming the string, I would like to get the position from the right side. Is there anyway to do this in the field calculator?
Here is the specific case of application:
I wanted to get the part of the string in "FolderPath" up the first '/' from the right.
You can use a regular expression with the field calculator function regexp_replace() on a NEW field like:
regexp_replace("input_field",'(/.*$)','/')
That one will keep the / but if you want the / removed, use:
regexp_replace("test_regex",'(/.*$)','')
Explanation:
The regular expression being used is /.*$
/ --look for a forward slash
. --identify any character (strings/numbers/special) after the slash except newlines
* --keep searching for any characters after the slash
$ --until the end of the string is reached
Since the number of characters is same, you can use substr() function on a new field as in the following expression:
substr( "Location" ,17,6)
In the above example I used Path instead of Location
Best Answer
I would use
regexp_substrinstead ofstrposso in your example something like:The first item (
"FolderPath") is your column name (enclosed in"), the second is a standard python regular expression. There is a regexp howto available to help you out.