Python Data Automation · Chapter 4 of 10

File Handling

Read and write text, CSV, and JSON files safely with context managers, encoding control, and schema checks.

Why this chapter matters

Reliable file handling prevents data corruption, leaked file handles, and silent parsing errors in automation pipelines.

What you will learn

  • Use with open(...) to manage file lifecycle safely.
  • Parse CSV and JSON with standard library tools.
  • Validate required fields before downstream processing.

Lessons in this chapter

  1. Context managersOpen files safely and close them automatically.
  2. CSV workflowsRead and write tabular files with predictable formatting.
  3. JSON workflowsLoad and validate structured payloads.
  4. Guide: file handlingProduce clean derived artifacts from raw files. Read the full guide →

Study task

Load orders.csv, validate required columns, and write a cleaned summary.csv that includes total revenue by channel.

Chapter checkpoint

Why is explicit encoding (for example utf-8) important when opening files?

It avoids environment-dependent behavior and reduces read or parse failures across systems.