Python File Handling

Introduction

Learn to read, write, and manage files in Python. Covers text, CSV, JSON, and basic error handling.

Description

Python provides simple and versatile methods to read, write, and manipulate files. It supports text, binary, CSV, JSON, and other formats for data storage and exchange.

Main Content

### File Handling Basics - **Opening Files** – Use `open(filename, mode)` with modes: 'r' (read), 'w' (write), 'a' (append), 'rb', 'wb'. - **Reading Files** – `read()`, `readline()`, `readlines()` methods. - **Writing Files** – `write()` and `writelines()`. - **Closing Files** – `close()` method or use `with` statement for automatic closure. ### Working with CSV and JSON - **CSV** – Use `csv` module to read/write structured data. - **JSON** – Use `json` module to parse and dump JSON data. ### Error Handling - Use `try-except` blocks to handle file-related exceptions like `FileNotFoundError` or `IOError`. ### Best Practices - Always close files or use `with` context. - Handle exceptions to avoid crashes. - Use appropriate file modes to prevent data loss.

Conclusion

Python file handling allows efficient reading, writing, and management of various file formats. Mastering these techniques is essential for data processing and automation tasks.

Interview Questions

• How do you open and read a file in Python?
• Explain how to write data to a CSV file using Python.
• How do you handle JSON files in Python?
• What is the advantage of using 'with' statement for file handling?
• How do you handle file-related exceptions?

Key Takeaways

• Python provides versatile file handling for text, CSV, JSON, and binary files.
• Use `with` to ensure files are properly closed.
• Always handle exceptions to prevent runtime errors.
• Modules like `csv` and `json` simplify structured data operations.
• File modes control read/write/append operations.