# Node Development **URL:** https://forum.knime.com/c/node-development/21.md [Latest](https://forum.knime.com/latest.md) · [Categories](https://forum.knime.com/categories.md) · [Tags](https://forum.knime.com/tags.md) --- ## [Attention: This category is for discussing development of KNIME software and nodes - not workflows!](https://forum.knime.com/t/attention-this-category-is-for-discussing-development-of-knime-software-and-nodes-not-workflows/37823)
**Author:** [@ScottF](https://forum.knime.com/u/ScottF)\ **Replies:** 0\ **Last updated:** [December 3, 2021, 4:14pm UTC](https://forum.knime.com/t/attention-this-category-is-for-discussing-development-of-knime-software-and-nodes-not-workflows/37823 "2021-12-03T16:14:54Z")
If you have questions about a workflow, you can post that in the main KNIME Analytics Platform category. (Bonus: that area gets the most views anyway.) If you have feature suggestions, you can post those in the Feedback… --- ## [About the Node Development category](https://forum.knime.com/t/about-the-node-development-category/85)
**Author:** [@system](https://forum.knime.com/u/system)\ **Replies:** 0\ **Last updated:** [February 26, 2018, 6:42pm UTC](https://forum.knime.com/t/about-the-node-development-category/85 "2018-02-26T18:42:10Z")
For discussions related to KNIME development and implementing your own KNIME nodes or enhancing KNIME. You can find more information about how to develop your own KNIME nodes here https://www.knime.com/developers --- ## [Python based Extension Development API: DoubleParameter can't display inf or nan](https://forum.knime.com/t/python-based-extension-development-api-doubleparameter-cant-display-inf-or-nan/91935)
**Author:** [@joh\_elf](https://forum.knime.com/u/joh_elf)\ **Replies:** 1\ **Last updated:** [May 18, 2026, 6:18pm UTC](https://forum.knime.com/t/python-based-extension-development-api-doubleparameter-cant-display-inf-or-nan/91935 "2026-05-18T18:18:26Z")
Hi, the knext.DoubleParameter can’t display inf or NaN values, which is quite important f.i. for default values of filters or alike. This max\_lim: knext.DoubleParameter = knext.DoubleParameter( label=“Max. Limit”,… --- ## [Python based Extension Development API: ColumnParameter for input\_table\_group](https://forum.knime.com/t/python-based-extension-development-api-columnparameter-for-input-table-group/91918)
**Author:** [@joh\_elf](https://forum.knime.com/u/joh_elf)\ **Replies:** 1\ **Last updated:** [May 18, 2026, 6:17pm UTC](https://forum.knime.com/t/python-based-extension-development-api-columnparameter-for-input-table-group/91918 "2026-05-18T18:17:50Z")
Hi all, I’m using the Python Extension Development API. I want to set up a node with input\_table\_group to support an arbitrary number of input tables together with a ColumnParameter ParameterArray to select one column f… --- ## [KNIME to Python Exporter: Roadmap for Additional Node Support](https://forum.knime.com/t/knime-to-python-exporter-roadmap-for-additional-node-support/91874)
**Author:** [@VitaliiKaplan](https://forum.knime.com/u/VitaliiKaplan)\ **Replies:** 6\ **Last updated:** [May 1, 2026, 8:47pm UTC](https://forum.knime.com/t/knime-to-python-exporter-roadmap-for-additional-node-support/91874 "2026-05-01T20:47:21Z")
Dear KNIME users, I want to thank you for using k2pweb and knime2py and share news from During the last two months, I collected workflow profiles and web service usage logs. This helped me fix one race-condition issu… --- ## [Resources on creating extensions/nodes](https://forum.knime.com/t/resources-on-creating-extensions-nodes/91849)
**Author:** [@Marc\_Goossens](https://forum.knime.com/u/Marc_Goossens)\ **Replies:** 0\ **Last updated:** [April 24, 2026, 11:51am UTC](https://forum.knime.com/t/resources-on-creating-extensions-nodes/91849 "2026-04-24T11:51:03Z")
Hello all, Does anyone know if there are any good resources out there about node and/or extension development? I am thinking about ‘for dummies’ and intermediate levels. Free stuff, stuff you have to pay for, books on … --- ## [Soumitra Dutta Oxford: How do I create and configure my own KNIME node?](https://forum.knime.com/t/soumitra-dutta-oxford-how-do-i-create-and-configure-my-own-knime-node/91641)
**Author:** [@soumitradutta26](https://forum.knime.com/u/soumitradutta26)\ **Replies:** 3\ **Last updated:** [March 21, 2026, 8:07pm UTC](https://forum.knime.com/t/soumitra-dutta-oxford-how-do-i-create-and-configure-my-own-knime-node/91641 "2026-03-21T20:07:10Z")
Hi Everyone, I’m Soumitra Dutta – Entrepreneur & Photographer Based in Oxford. I’m trying to create and configure my own KNIME node, but I’m not sure about the best approach. Could anyone share their tips, recommended pr… --- ## [Python Extension Development (Labs): View node with output table](https://forum.knime.com/t/python-extension-development-labs-view-node-with-output-table/91448)
**Author:** [@joh\_elf](https://forum.knime.com/u/joh_elf)\ **Replies:** 0\ **Last updated:** [February 18, 2026, 3:06pm UTC](https://forum.knime.com/t/python-extension-development-labs-view-node-with-output-table/91448 "2026-02-18T15:06:08Z")
Hi all, using the Python Extension Development API I’m trying to develop a view node which displays a matplotlib plot and returns an output table at the same time. Unluckily, during execution this results in the follow… --- ## [Minimal root log level in log4j3.xml overrides level set in preferences of KNIME AP](https://forum.knime.com/t/minimal-root-log-level-in-log4j3-xml-overrides-level-set-in-preferences-of-knime-ap/91353)
**Author:** [@frederik](https://forum.knime.com/u/frederik)\ **Replies:** 2\ **Last updated:** [February 12, 2026, 8:54am UTC](https://forum.knime.com/t/minimal-root-log-level-in-log4j3-xml-overrides-level-set-in-preferences-of-knime-ap/91353 "2026-02-12T08:54:12Z")
I noticed that INFO-level log messages created by the NodeLogger in my Java-developed custom nodes no longer appear in the knime.log file or in the KNIME console, even though the Log Level configuration in File \> Prefere… --- ## [Python Extension Dev: Node with PyQt6/PySide6 Widget freezes on show()](https://forum.knime.com/t/python-extension-dev-node-with-pyqt6-pyside6-widget-freezes-on-show/91156)
**Author:** [@joh\_elf](https://forum.knime.com/u/joh_elf)\ **Replies:** 13\ **Last updated:** [February 9, 2026, 1:46pm UTC](https://forum.knime.com/t/python-extension-dev-node-with-pyqt6-pyside6-widget-freezes-on-show/91156 "2026-02-09T13:46:37Z")
Dear all, using the new Python Extension Development (Labs) documented here Pure Python Node Extensions Guide | KNIME Documentation and here Python Extension Development (Labs) — KNIME Python API documentation I’m curre… --- ## [modern UI - change widget value only if condition met](https://forum.knime.com/t/modern-ui-change-widget-value-only-if-condition-met/91195)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 1\ **Last updated:** [February 6, 2026, 4:00pm UTC](https://forum.knime.com/t/modern-ui-change-widget-value-only-if-condition-met/91195 "2026-02-06T16:00:46Z")
Hi, I try to implement a widget\_1 which will change its value only if another widget\_2 is set to a specific value. otherwise I would like to let the value of widget\_1 untouched. I tried to use a @ValueProvider (computeF… --- ## [KNIME AP 5.8.2 Modern UI — Can we replace the node configuration dialog with an external Chromium window on Configure click?](https://forum.knime.com/t/knime-ap-5-8-2-modern-ui-can-we-replace-the-node-configuration-dialog-with-an-external-chromium-window-on-configure-click/91311)
**Author:** [@jspark123](https://forum.knime.com/u/jspark123)\ **Replies:** 1\ **Last updated:** [February 2, 2026, 9:12am UTC](https://forum.knime.com/t/knime-ap-5-8-2-modern-ui-can-we-replace-the-node-configuration-dialog-with-an-external-chromium-window-on-configure-click/91311 "2026-02-02T09:12:46Z")
Hello everyone, We are developing a custom node on KNIME Analytics Platform 5.8.2 with Modern UI. Requirement: When the user clicks the node’s “Configuration” / Configure button, we want to prevent the default co… --- ## [Python Extension Node - Table metadata interface](https://forum.knime.com/t/python-extension-node-table-metadata-interface/91203)
**Author:** [@joh\_elf](https://forum.knime.com/u/joh_elf)\ **Replies:** 0\ **Last updated:** [January 15, 2026, 11:46am UTC](https://forum.knime.com/t/python-extension-node-table-metadata-interface/91203 "2026-01-15T11:46:48Z")
Dear all, In my Python-based Nodes implemented via the Knime Python Extension Development API I’d like to make use of table metadata of the following kind: per-table metadata: dict-like metadata which applies to the w… --- ## [Python Extension Dev: Maximum Recursion Depth Exceeded when configuring logger](https://forum.knime.com/t/python-extension-dev-maximum-recursion-depth-exceeded-when-configuring-logger/91180)
**Author:** [@joh\_elf](https://forum.knime.com/u/joh_elf)\ **Replies:** 2\ **Last updated:** [January 14, 2026, 12:00pm UTC](https://forum.knime.com/t/python-extension-dev-maximum-recursion-depth-exceeded-when-configuring-logger/91180 "2026-01-14T12:00:28Z")
Dear all, while developing my own Python Extension using the new Pure Python Node Extensions Guide | KNIME Documentation , I stumbled upon a RecursionError: maximum recursion depth exceeded when trying to import a s… --- ## [Beginner Developer: Python extension](https://forum.knime.com/t/beginner-developer-python-extension/90224)
**Author:** [@HQ\_Best\_QH](https://forum.knime.com/u/HQ_Best_QH)\ **Replies:** 13\ **Last updated:** [January 12, 2026, 8:03pm UTC](https://forum.knime.com/t/beginner-developer-python-extension/90224 "2026-01-12T20:03:51Z")
Hi, im trying to create a python extension, i tried following both java and python tutorials with no luck in the last few days - in the end node could not be recognised and ive decided to just give up on using IDE - jus… --- ## [Issue with Optional\ widget](https://forum.knime.com/t/issue-with-optional-enum-widget/90985)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 0\ **Last updated:** [December 16, 2025, 10:04am UTC](https://forum.knime.com/t/issue-with-optional-enum-widget/90985 "2025-12-16T10:04:12Z")
Hello, Not sure if I am doing something wrong but the following widget definition ignores the given title (and shows no description button). The widget name is generated from the variable name and displayed as “My Test … --- ## [Troubleshooting help wanted - Issue with KNIME SDK](https://forum.knime.com/t/troubleshooting-help-wanted-issue-with-knime-sdk/90870)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 1\ **Last updated:** [December 4, 2025, 9:29am UTC](https://forum.knime.com/t/troubleshooting-help-wanted-issue-with-knime-sdk/90870 "2025-12-04T09:29:46Z")
Hi, I had a working SDK with KNIME nightly until yesterday. Then, I got weird errors when starting KNIME. I decided to throw away my Eclipse workspace, I checked out releases/SDK from the knime SDK repo, created a fresh… --- ## [Preview of KNIME Analytics Platform 5.9.0](https://forum.knime.com/t/preview-of-knime-analytics-platform-5-9-0/90374)
**Author:** [@wiswedel](https://forum.knime.com/u/wiswedel)\ **Replies:** 32\ **Last updated:** [November 25, 2025, 12:12pm UTC](https://forum.knime.com/t/preview-of-knime-analytics-platform-5-9-0/90374 "2025-11-25T12:12:37Z")
Dear community developers: We’d like to draw your attention to a preview of KNIME Analytics Platform 5.9.0, which is scheduled to be released at the end of November. This is especially important if you have built custom… --- ## [enable or disable a field based on the presence of domain values of a selected column?](https://forum.knime.com/t/enable-or-disable-a-field-based-on-the-presence-of-domain-values-of-a-selected-column/90319)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 2\ **Last updated:** [November 24, 2025, 12:23pm UTC](https://forum.knime.com/t/enable-or-disable-a-field-based-on-the-presence-of-domain-values-of-a-selected-column/90319 "2025-11-24T12:23:45Z")
Sorry for all these very specific questions but I try to implement a node where the user can select a single column. If this column does have domain values a checkbox should be enabled (not set). Is that possible? I did … --- ## [output\_view as output\_table](https://forum.knime.com/t/output-view-as-output-table/90658)
**Author:** [@rryu](https://forum.knime.com/u/rryu)\ **Replies:** 0\ **Last updated:** [November 17, 2025, 11:46am UTC](https://forum.knime.com/t/output-view-as-output-table/90658 "2025-11-17T11:46:43Z")
Similar to Python View output data table - KNIME Analytics Platform - KNIME Community Forum. To summarise, I need rich context-aware UI, e.g. adding new rows showing non-null counts, distinct values, etc. This can be a… --- ## [behaviour with default settings of optional widgets](https://forum.knime.com/t/behaviour-with-default-settings-of-optional-widgets/90621)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 0\ **Last updated:** [November 12, 2025, 2:20pm UTC](https://forum.knime.com/t/behaviour-with-default-settings-of-optional-widgets/90621 "2025-11-12T14:20:09Z")
While implementing my own node with an @OptionalWidget setting, I came across the following behavior which is probably not wanted? Instead of putting my own code here I first confirmed the behavior on the implementation … --- ## [Question to WidgetGroup and Effects](https://forum.knime.com/t/question-to-widgetgroup-and-effects/90526)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 3\ **Last updated:** [November 6, 2025, 2:14pm UTC](https://forum.knime.com/t/question-to-widgetgroup-and-effects/90526 "2025-11-06T14:14:12Z")
Hi, let me first explain what I would like to do (though I have no clue whether I’ve chosen the right approach…) I would like to have a checkbox. If it’s checked several different widgets should be enabled. I’ve made a… --- ## [@OptionalWidget for Enum?](https://forum.knime.com/t/optionalwidget-for-enum/90291)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 2\ **Last updated:** [November 3, 2025, 1:10pm UTC](https://forum.knime.com/t/optionalwidget-for-enum/90291 "2025-11-03T13:10:14Z")
Hi, I try to provide a drop down list as an optional widget in my node settings. First question: Should that be possible? If not, I could still use a @ValueSwitchWidget to show or hide my setting. If yes, let me descri… --- ## [create new column - best practice question](https://forum.knime.com/t/create-new-column-best-practice-question/90138)
**Author:** [@niederle](https://forum.knime.com/u/niederle)\ **Replies:** 3\ **Last updated:** [October 24, 2025, 8:34am UTC](https://forum.knime.com/t/create-new-column-best-practice-question/90138 "2025-10-24T08:34:04Z")
Hi, I have a very basic question. I have a (java based) node which will create a new column. The user can provide the name of the new column via TextInputWidget. I added the column name validation pattern which will sho… --- ## [Request for Help on Workflow Naming Issue](https://forum.knime.com/t/request-for-help-on-workflow-naming-issue/90207)
**Author:** [@taylorpeter55](https://forum.knime.com/u/taylorpeter55)\ **Replies:** 5\ **Last updated:** [October 16, 2025, 8:24am UTC](https://forum.knime.com/t/request-for-help-on-workflow-naming-issue/90207 "2025-10-16T08:24:52Z")
Hi all, I’m looking for assistance with a challenge regarding our workflow management please. Current Situation Our workflows rely on an offline Excel file to pull additional fields. I currently use the ‘Extract Conte… --- ## [Ajay Hinduja Switzerland ~ How do I make ports of a node accept tuples as inputs or outputs?](https://forum.knime.com/t/ajay-hinduja-switzerland-how-do-i-make-ports-of-a-node-accept-tuples-as-inputs-or-outputs/89965)
**Author:** [@ajayhinduja09](https://forum.knime.com/u/ajayhinduja09)\ **Replies:** 1\ **Last updated:** [September 19, 2025, 2:25pm UTC](https://forum.knime.com/t/ajay-hinduja-switzerland-how-do-i-make-ports-of-a-node-accept-tuples-as-inputs-or-outputs/89965 "2025-09-19T14:25:18Z")
Hi Everyone, I’m Ajay Hinduja. Born in Punjab, India, and now living in Geneva, Switzerland (Swiss). I’m looking to understand how to make the ports of a KNIME node accept tuples as inputs or outputs. Has anyone worked o… --- ## [Adding the possibility to add a parameter in configuration dialogue for a Custom Python based KNIME Node](https://forum.knime.com/t/adding-the-possibility-to-add-a-parameter-in-configuration-dialogue-for-a-custom-python-based-knime-node/78401)
**Author:** [@Vits](https://forum.knime.com/u/Vits)\ **Replies:** 2\ **Last updated:** [September 17, 2025, 4:53pm UTC](https://forum.knime.com/t/adding-the-possibility-to-add-a-parameter-in-configuration-dialogue-for-a-custom-python-based-knime-node/78401 "2025-09-17T16:53:53Z")
Hello, I’m currently trying to define a new Python based KNIME Node. I’m trying to build a configuration dialogue where a user has the possibility to add a string parameter. I saw this in other KNIME Nodes: Is ther… --- ## [(Conda) Package versions](https://forum.knime.com/t/conda-package-versions/89864)
**Author:** [@ricciV1](https://forum.knime.com/u/ricciV1)\ **Replies:** 3\ **Last updated:** [September 11, 2025, 4:19pm UTC](https://forum.knime.com/t/conda-package-versions/89864 "2025-09-11T16:19:23Z")
Hey KNIMErs! I have a question reagrding (python) node development. The question is towards the versioning of packages that e.g. are available in conda. E.g. there is a version of “knime-extension“ with tag “main” whi… --- ## [Enable to bundle python extension: process wait in mnv package step](https://forum.knime.com/t/enable-to-bundle-python-extension-process-wait-in-mnv-package-step/89388)
**Author:** [@OS\_KNIME](https://forum.knime.com/u/OS_KNIME)\ **Replies:** 2\ **Last updated:** [September 1, 2025, 12:10pm UTC](https://forum.knime.com/t/enable-to-bundle-python-extension-process-wait-in-mnv-package-step/89388 "2025-09-01T12:10:19Z")
When trying to bundle my python extension to share it I still stuck on the ‘mvn package’ step without any error message or sign that something is progressing. I’m working on 5.2 version. Olivier --- ## [Category for a new node using Modern UI](https://forum.knime.com/t/category-for-a-new-node-using-modern-ui/89090)
**Author:** [@trj](https://forum.knime.com/u/trj)\ **Replies:** 2\ **Last updated:** [August 15, 2025, 5:34am UTC](https://forum.knime.com/t/category-for-a-new-node-using-modern-ui/89090 "2025-08-15T05:34:50Z")
Hi team, I am trying to define a category for the node I am developing. Using the decorator, I can assign the new node to a custom category in the classic interface. But this doesn’t apply to the modern UI (See below C… [Next page](https://forum.knime.com/c/node-development/21.md?page=1)