# Executing python expression from module **URL:** \ **Category:** Module Development\ **Tags:** ignition79, scripting\ **Created:** [October 3, 2017, 11:38am UTC](https://forum.inductiveautomation.com/t/executing-python-expression-from-module/15544 "2017-10-03T11:38:28Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![a.bolatov](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@a.bolatov](https://forum.inductiveautomation.com/u/a.bolatov)\ **Post date:** [October 3, 2017, 11:38am UTC](https://forum.inductiveautomation.com/t/executing-python-expression-from-module/15544/1 "2017-10-03T11:38:28Z")
I’d like to execute a python expression and get the result as a String from inside my module. There is a swing component which has dynamic title. Let’s say, I pass python expression ‘now(1000)’, without quotes, through property editor and the title will be dynamically showing datetime string. According to the answer from @Carl.Gould at [this thread](http://forum.inductiveautomation.com/t/designer-out-of-memory-error/6493/5) I have created a `ScriptRunner` class. ```auto public class ScriptRunner { private final Logger logger = LoggerFactory.getLogger(getClass()); private final ScriptManager scriptManager; public ScriptRunner(ScriptManager scriptManager) { assert scriptManager != null : "ScriptManager cannot be null"; this.scriptManager = scriptManager; } public String runIt(String scriptCode) { if (StringUtils.isBlank(scriptCode)) { logger.debug("runIt(ScriptCode) is null or empty"); return ""; } PyObject compiledScript = Py.compile_command_flags(scriptCode, "", CompileMode.eval, CompilerFlags.getCompilerFlags(), false); try { return scriptManager.runFunction(compiledScript).asString(); } catch (JythonExecException | NullPointerException e) { logger.error("Error running {}", scriptCode, e); } return "NO_RESULT"; } } ``` I get an instance of the `ScriptManager` from the component by calling: ```auto VisionClientContext context = getAppContext(); ScriptManager scriptManager = context.getScriptManager(); this.scriptRunner = new ScriptRunner(scriptManager); ``` Unfortunately, when I call `scriptRunner.runIt("now(1000)")` I get an exception: ```auto com.inductiveautomation.ignition.common.script.JythonExecException: TypeError: 'tablecode' object is not callable at org.python.core.Py.TypeError(Py.java:235) at org.python.core.PyObject. __call__ (PyObject.java:316) at org.python.core.PyObject. __call__ (PyObject.java:357) at com.inductiveautomation.ignition.common.script.ScriptManager.runFunction(ScriptManager.java:670) at mycompany.ScriptRunner.runIt(ScriptRunner.java:35) ``` Could help figuring this out? Thanks in advance, Almer ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [October 3, 2017, 11:46am UTC](https://forum.inductiveautomation.com/t/executing-python-expression-from-module/15544/2 "2017-10-03T11:46:05Z")
`now()` is part of our expression language, which is an entirely separate thing from executing arbitrary Jython code. ---
**Author:** ![a.bolatov](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@a.bolatov](https://forum.inductiveautomation.com/u/a.bolatov)\ **Post date:** [October 3, 2017, 11:48am UTC](https://forum.inductiveautomation.com/t/executing-python-expression-from-module/15544/3 "2017-10-03T11:48:16Z")
Hi @Kevin.Herron , I am new to Ignition platform. I might have mis-explained my problem. What if I only want to execute Ignition expressions and get back the results as string, for example? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [October 3, 2017, 11:54am UTC](https://forum.inductiveautomation.com/t/executing-python-expression-from-module/15544/4 "2017-10-03T11:54:35Z")
[This post](http://forum.inductiveautomation.com/t/alarmnotification-how-to-parse-expressions-in-a-property/7655) may be helpful. You can ignore the alarm-specific parts, but basically what you need is an `ExpressionParseContext`. Searching for that term yields a couple other results too. ---
**Author:** ![a.bolatov](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@a.bolatov](https://forum.inductiveautomation.com/u/a.bolatov)\ **Post date:** [October 4, 2017, 9:48am UTC](https://forum.inductiveautomation.com/t/executing-python-expression-from-module/15544/5 "2017-10-04T09:48:39Z")
Hi @Kevin.Herron, thanks, I got it working using [this class you wrote](http://forum.inductiveautomation.com/t/expression-parsing/9170/7) and [this usage example](http://forum.inductiveautomation.com/t/expression-parsing/9170/5). In case if anyone needs a running example, I will leave the following code snippets here: ```auto public class CustomParseContext implements ExpressionParseContext { private final TagManagerBase tagManagerBase; private final FunctionFactory functionFactory; public CustomParseContext(TagManagerBase tagManagerBase, FunctionFactory functionFactory) { this.tagManagerBase = tagManagerBase; this.functionFactory = functionFactory; } @Override public Expression createBoundExpression(String path) throws RuntimeException { try { TagPath tagPath = TagPathParser.parse(path); Tag tag = tagManagerBase.getTag(tagPath); if (tag == null) throw new TagNotFoundException(tagPath); TagValue tagValue = tag.getAttribute(tagPath.getProperty()); TagListener listener = new TagListener( tagPath, tagValue.getValue(), tagValue.getQuality() ); Class type = TagProp.Value.equals(tagPath.getProperty()) ? tag.getDataType().getJavaType() : tagPath.getProperty().getType(); BoundTagExpression expression = new BoundTagExpression(tagPath); expression.setType(type); expression.setTagListenerDelegate(listener); return expression; } catch (IllegalArgumentException | IOException | TagNotFoundException e) { throw new RuntimeException(e); } } @Override public FunctionFactory getFunctionFactory() { return functionFactory; } } ``` ```auto public class MyComponent extends AbstractVisionPanel { private final Logger logger = LoggerFactory.getLogger(getClass()); ... @Override protected void onStartup() { super.onStartup(); VisionClientContext appContext = getAppContext(); FunctionFactory functionFactory = appContext.getExpressionFunctionFactory(); ClientTagManager tagManager = appContext.getTagManager(); CustomParseContext customParseContext = new CustomParseContext(tagManager, functionFactory); Parser parser = new ELParserHarness(); String expressionString = "now(1000)"; try { Expression expression = parser.parse(expressionString, customParseContext); expression.connect(appContext, () -> { try { logger.debug("updating"); String value = TypeUtilities.toString(expression.execute().getValue()); System.out.printf("value = %s\n", value); } catch (ExpressionException e) { logger.warn("Error parsing expression '{}'", expressionString); } }); expression.startup(); // Execute the expression 'now(1000)' once System.out.println("execute: " + TypeUtilities.toString(expression.execute().getValue())); } catch (Exception e) { logger.error("Error starting ELParser", e); } } ... } ``` **I will mark this question as solved if you don’t mind**