I’m trying to handle Python script (that returns list of strings, e.g. ['1', '2', '3', 'latest']) output with Groovy (on Jenkins):
def task = "python3 $JENKINS_HOME/scripts/my_script.py -p some_parameter".execute()
task.waitFor()
def buildNumbers = task.text
// println buildNumbers returns the list as it is - ['1', '2', '3', 'latest']
Now I want to create HTML select node with all the elements from buildNumbers list as option nodes:
def htmlOptions = buildNumbers.collect { "<option value='${it}'>${it}</option>" }.join('n')
def htmlSelect = "<select name='SDK_version'>" + htmlOptions + "</select>"
return htmlSelect
I expect to get
<select>
<option>1</option>
<option>2</option>
<option>3</option>
<option>latest</option>
</select>but instead it looks like
<select>
<option>[</option>
<option>'</option>
<option>1</option>
<option>'</option>
...
</select>What should I change to make buildNumbers looks like a list, but not string?
The issue is that the output of your Python script is a string that looks like a list, not an actual list. When you call task.text, you’re getting the entire output of the script as a single string.
To convert this string into a list of strings in Groovy, you can use the JsonSlurper class to parse JSON-formatted strings.
import groovy.json.JsonSlurper
def task = "python3 $JENKINS_HOME/scripts/my_script.py -p some_parameter".execute()
task.waitFor()
def buildNumbers = new JsonSlurper().parseText(task.text.trim())
def htmlOptions = buildNumbers.collect { "<option value='${it}'>${it}</option>" }.join('n')
def htmlSelect = "<select name='SDK_version'>" + htmlOptions + "</select>"
return htmlSelect
This script uses JsonSlurper().parseText() to parse the output of your Python script into a list of strings. The trim() function is just to remove any leading or trailing whitespace from the output.
2
Your suggestion here with Eval.me() is really a hack. Think about it, you evaluate the output of the python script as a groovy script! Yes, accidentally python lists serialize into something that happens to be a valid groovy list, but what if it’s a python dictionary or tuple? What if the strings have different escaping rules? It’s just a bad idea.
Output json from your python script and parse json in your groovy script. It’s a much happier place.