Bug and impact

The recently added source/load_mod_from_source_code.py example crashed on every execution because the dynamically executed snippet referenced an undefined name. Any user running the example hit a NameError instead of seeing the intended loaded value.

Root cause

The script executed a=b inside an otherwise empty namespace, so b was unresolved during exec.

Fix

Changed the snippet to assign the literal string value (a='b') and added a standard-library unittest regression test that executes the script as a subprocess.

Validation

• python3 source/load_mod_from_source_code.py
• python3 -m unittest discover -s tests -v