Table of Contents

1. Python - File handling
   1. Open
   2. Create
   3. Update
   4. Delete
   5. Folder Management

Introduction

File handling is a crucial aspect of programming, allowing you to interact with files on your system. Python provides a simple and efficient way to work with files, enabling you to read data, write data, and manipulate files in various ways.

Python - File handling

Open

The foundation of file handling in Python lies in the open() function. It opens a file, allowing you to read from it or write to it. The syntax is:

file_object = open(file_path, mode)

where:

• file_object: This is a variable that will hold a reference to the opened file.
• file_path: This is the path to the file you want to open (e.g., "myfile.txt").
• mode: This specifies the mode in which you want to open the file. Here are some common modes:

Mode	Description
'r'	Read mode (default). Opens the file for reading.
'w'	Write mode. Opens the file for writing (overwrites existing content or creates a new file).
'a'	Append mode. Opens the file for appending (adds content to the end of the file).
'x'	Create mode. Creates a new file for writing. Raises an error if the file already exists.
'b'	Binary mode. Opens the file in binary mode (useful for images, audio, etc.).
't'	Text mode (default). Opens the file in text mode.
'+'	Allows both reading and writing to the file.

Create

To create a new file, use the 'w' or 'x' modes with the open() function. If the file already exists, 'w' will overwrite it, while 'x' will raise an error.

file_object = open("new_file.txt", "w")

Update

Updating a file in Python involves reading its content, modifying it, and writing the updated content back to the file. You can use the 'r+' or 'w+' modes for this purpose.

with open("my_file.txt", "r+") as file_object:
  content = file_object.read()
  # Modify the content as needed
  file_object.seek(0)  # Go to the beginning of the file
  file_object.write(modified_content)

Delete

Python doesn't have a built-in function to directly delete files. Instead, you can use the os.remove() function from the os module.

import os

os.remove("file_to_delete.txt")

Folder Management

You can use the os module to manage folders (directories) as well:

• os.mkdir("new_folder"): Creates a new directory.
• os.rmdir("folder_to_delete"): Removes an empty directory.
• os.listdir("path/to/directory"): Returns a list of files and subdirectories in a directory.
• os.rename("old_name.txt", "new_name.txt"): Renames a file or directory.
• os.path.exists("path/to/file"): Checks if a file or directory exists.

Summary

• The open() function is the core of file handling in Python.
• Use different modes ('r', 'w', 'a', etc.) to read, write, append, or create files.
• The os module provides functions for directory management.
• Remember to close files using file_object.close() or use the with statement for automatic closure.