QGIS Field Calculator – Removing String to the Right of a Character

field-calculatorqgis

I have a string field and I want to delete the part of the string after a specific character in this case a '/'. I am looking for a way to do this using the field calculator in QGIS.

I know I can use the replace function to replace a specific string but I need a way to do this with a wildcard as the strings after the '/' character are not the same in the table.

Best Answer

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

Related Solutions

Remove Newline Character Python – Removing Return/Newline Character from Field Using Python

I think this is just a bug/limitation of the Python parser with the field calculator/Calculate Field tool. If a newline is encountered within the text field, a SyntaxError: EOL while scanning string literal occurs no matter what you try.

I can reproduce the issue at 10.1 SP1 by importing the following CSV file into a file geodatabase, adding a field and simply attempting to copy the Text field to the new field using the Field Calculator with the Python parser and and the expression !Text!.

ID,Text
1,"this is a multiline 
example"

Try switching to the VB parser, or using an UpdateCursor and avoiding the Field Calculator entirely.

This issue is also discussed on the ESRI forums, with the same conclusions:

End-of-line (EOL) Problem

The only relevant NIM I could find was this:

NIM085499 - CalculateField calculations using non-ASCII characters fail on a Linux engine with: "ERROR 000539: SyntaxError: EOL while scanning string literal (, line 1)".

[GIS] Using replace string function in QGIS Field Calculator

replace( '(B)','(B)','County')

tells QGIS to replace the '(B)' in '(B)' with 'Country'.

You want

replace("Name",'(B)','Country')

= replace the '(B)' in "Name" with 'Country'.

Note that the double quotes indicate a field name while the single quotes refer to a static string. These are not interchangeable.

Best Answer

Related Solutions

Remove Newline Character Python – Removing Return/Newline Character from Field Using Python

[GIS] Using replace string function in QGIS Field Calculator

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