Python Module Not Found in Production Script

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Python apps depend on interpreter-specific package environments.

Environment & Reproduction

Script exits with ModuleNotFoundError for expected dependency.

Root Cause Analysis

Cron, systemd, or shell jobs using different interpreter paths.

Quick Triage

Package installed in one environment while runtime uses another.

Step-by-Step Diagnosis

Capture python executable path and installed module list.

Solution – Primary Fix

Install missing dependency into active runtime environment.

Solution – Alternative Approaches

Pin dependencies and enforce virtualenv activation in service definitions.

Verification & Acceptance Criteria

Run script successfully with no import errors.

Rollback Plan

Use reproducible lock files and deployment environment checks.

Prevention & Hardening

Alert on repeated import failures in task logs.

Related Errors & Cross-Refs

Rollback to previous environment snapshot if dependency upgrade breaks runtime.

Related tutorial: View the step-by-step tutorial for debian-10.

View all debian-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Python packaging practices and Debian Python environment guidance.