`logging.basicConfig(...)` at import time reconfigures the root logger for the whole process

[rwest]

Summary
pysidt/sidt.py calls logging.basicConfig(level=logging.INFO) at module import time (line 28), and logs throughout via the root logger (logging.info(...), logging.warning(...), etc.). Both are discouraged for libraries: importing PySIDT silently reconfigures logging for any program that imports it (directly or transitively).

Why this is a problem
A library shouldn't configure the root logger — that's the application's responsibility. The Python "Logging HOWTO" → Configuring Logging for a Library recommends a library add at most a NullHandler and leave configuration to the app.

The current behavior has two side effects on consumers:

1. basicConfig(level=logging.INFO) at import forces the root logger to INFO and attaches a stderr handler for the entire process. Any program that imports PySIDT (or imports something that imports it) inherits this.
2. Logging through the root logger (rather than a module-level named logger) means PySIDT's messages aren't namespaced, so consumers can't selectively adjust PySIDT's verbosity without affecting their whole application.

How we hit it
We import PySIDT transitively in RMG-Py (via rmgpy.data.thermo). A tool that emitted INFO logs suddenly started writing them to stderr — purely because importing PySIDT had switched the root logger to INFO + stderr. We worked around it with logging.basicConfig(level=logging.WARNING, force=True), but the root cause is upstream.

Suggested fix
Standard library-logging hygiene:

# pysidt/sidt.py
import logging

logger = logging.getLogger(__name__)   # module-level named logger
# (remove the logging.basicConfig(level=logging.INFO) call)

AI use
Issue drafted with help from Claude