Lecture on File Handling in Python

Introduction

• Sequential data types previously covered: lists, tuples, sets
• Basic operations and inbuilt functions discussed
• Focus today: Files in Python

Concept of Files

• Purpose: Store output data
• In programming, files allow the saving of output data
• Types of Files: Text Files & Binary Files

Basic File Operations

• Opening & Creating Files

  • Before reading or writing, a file must be created and opened
  • Use the open function to open/create files
  • Syntax: file_object = open('filename.txt', 'access_mode')
  • File object (file pointer) points to the file's content

• Access Modes

  • Define how files are to be accessed (read/write)
  • Primary Access Modes: R, W, A
    • r (Read Mode)
      • File should exist; file's content read-only
      • Pointer at the beginning of the file
    • w (Write Mode)
      • File opened for writing; overwrites existing content
      • If the file doesn't exist, a new file is created
    • a (Append Mode)
      • Append data to existing content
      • Pointer at the end; creates file if it doesn’t exist
  • Extended Access Modes
    • r+, w+, a+ for both reading and writing in text files
    • rb, wb, ab for binary files
    • rb+, wb+, ab+ for both reading and writing in binary files

• File Closing

  • It's the user's responsibility to close opened files
  • Syntax: file_object.close()
  • Example: fp = open('abc.txt', 'w') # perform operations fp.close()

Example

Summary

• Steps to handle files: Open, Read/Write, Close
• File creation: Occurs in write (w) and append (a) modes
• Importance of closing files after operations

Next Session: Reading & Writing Operations on Files

If there are any doubts or queries, feel free to ask in the comments.

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