Chapter 9: Working with Files and Directories

 

9.1 Introduction to
File and Directory Operations

9.1.1 Understanding
file paths and directory structures

Explanation: File paths
specify the location of a file or directory in the file system. Understanding
file paths and directory structures is crucial for working with files and
directories in Python.

Example:

 

python

///Example

file_path =
"path/to/file.txt"

directory_path =
"path/to/directory/"

9.1.2 Navigating and
manipulating file systems

Explanation: Python
provides various functions and methods to navigate and manipulate the file
system, such as creating, moving, renaming, and deleting files and directories.

Example:

 

python

///Example

import os

 

# Creating a directory

os.mkdir("new_directory")

 

# Renaming a file

os.rename("old_file.txt",
"new_file.txt")

 

# Deleting a directory

os.rmdir("old_directory")

9.1.3 Working with file
and directory permissions

Explanation: File and
directory permissions control who can read, write, or execute files and
directories. Python provides functions to set and retrieve file permissions.

Example:

 

python

///Example

import stat

 

# Setting file
permissions

os.chmod("file.txt",
stat.S_IRUSR | stat.S_IWUSR)  # Read and
write permissions for the owner

 

# Retrieving file
permissions

permissions =
stat.S_IMODE(os.lstat("file.txt").st_mode)

print(oct(permissions))  # Display permissions in octal format

9.2 File Operations

9.2.1 Opening and
closing files

Explanation: Files are
opened using the open() function, which returns a file object. Files should be
closed using the close() method to free system resources.

Example:

 

python

///Example

file =
open("file.txt", "r") 
# Open file in read mode

content = file.read()

print(content)

file.close()  # Close the file

9.2.2 Reading file
content

Explanation: File
content can be read using methods such as read(), readline(), or readlines().
These methods provide different ways to read the content of a file.

Example:

 

python

///Example

file =
open("file.txt", "r")

content =
file.read()  # Read entire content as a
string

print(content)

 

file.seek(0)  # Move the file pointer to the beginning

line =
file.readline()  # Read a single line

print(line)

 

file.seek(0)

lines =
file.readlines()  # Read all lines and
store them in a list

print(lines)

 

file.close()

9.2.3 Writing to files

Explanation: Files can
be opened in write mode to write content to them. The write() method is used to
write data to the file.

Example:

 

python

///Example

file =
open("file.txt", "w") 
# Open file in write mode

file.write("Hello,
World!")  # Write content to the
file

file.close()

9.3 Directory
Operations

9.3.1 Creating
directories

Explanation:
Directories can be created using the mkdir() function or the os.makedirs()
function. They provide a way to organize files into structured hierarchies.

Example:

 

python

///Example

import os

 

os.mkdir("new_directory")  # Create a new directory

os.makedirs("new_directory/sub_directory")  # Create nested directories

9.3.2 Listing directory
contents

Explanation: Python
provides functions to list the contents of a directory, including files and
subdirectories. These functions help in exploring and working with directory
structures.

Example:

 

python

///Example

import os

 

files =
os.listdir("directory")  # Get
a list of files and directories in the specified directory

for file in files:

    print(file)

9.3.3 Removing
directories

Explanation:
Directories can be removed using the rmdir() function or the os.removedirs()
function. Removing a directory deletes it along with its contents.

Example:

 

python

///Example

import os

 

os.rmdir("directory")  # Remove an empty directory

os.removedirs("directory/sub_directory")  # Remove nested directories

This chapter covers
file and directory operations in Python. Understanding how to navigate,
manipulate, and interact with files and directories is essential for many
programming tasks. The examples provided demonstrate the usage and syntax of
each topic, helping readers understand how to work with files and directories
in their own programs.