For ease of testing a WIP module, I will often start Slicer from a bash shell, so that I could save its output to a log programmatically. However, when I went to refactor my many print statements into logging calls, I noticed that they no longer appeared. Digging deeper, it seems that calling Slicer…

Slight correction; only some of the QT logs are placed in the Bash console; the “green” logs are Python only, further confusing things.

Have you tried adjusting the user setting for the logging level on the python console? See the following linked thread below: [image] Info level logging messages do not appear in Python console Development I built the latest Slicer 5.3, and I now see the changes in the Py…

Thank you for your response. I did check that; my “Log level” is currently set to Debug: [image] This is also an ERROR level logging message, so it should appear for any logging whatsoever. And it does; but only in the Python console, not Bash.

Console is only available in certain environments (e.g., no console on Windows GUI applications), so Slicer does not depend on it and I would not recommend for debugging. You can access logs in the application log file (slicer.app.errorLogModel().filePath). You can also add a callback function to t…

Ah; I was wondering how to access that message box. Will start pivoting to that then; thank you!

Large discrepancy in logged output in Python vs. Bash Consoles

Support

jamesobutler (James Butler) July 21, 2025, 2:05am 3

Have you tried adjusting the user setting for the logging level on the python console? See the following linked thread below:

Topic		Replies	Views
New feature: Python console displays more log messages Development feature , python	14	1432	April 10, 2023
Info level logging messages do not appear in Python console Development python	5	6022	November 15, 2023
Logging with a python script Support python	0	96	June 12, 2024
How to disable automatic logging into the Python Interactor? Development python	5	1310	October 28, 2022
How to use logging in an extension? Development python	1	697	December 6, 2022

Large discrepancy in logged output in Python vs. Bash Consoles

Related topics