Introduction

Theos library in Python serves as a cornerstone for interacting with the operating system, providing functions for file and directory manipulation, process management, environment variables, and more. This chapter delves into the myriad capabilities of theos module and demonstrates its utility through practical examples.

Topics

• File and directory operations
• Process management
• Environment variables manipulation

File and Directory Operations

Theos module offers a plethora of functions for performing file and directory operations, facilitating tasks such as file creation, deletion, renaming, and directory navigation.

Checks for the existence of a file

importos# Check if a file existsfile_path="example.txt"ifos.path.exists(file_path):print("File exists.")else:print("File does not exist.")

Output:

File does not exist.

Creates a new folder

importos# Create a directorydirectory_path="example_directory"os.mkdir(path=directory_path)print("Directory created.")

Output:

Directory created.

Renames a file

importos# Rename a filefile_path="example.txt"new_file_path="new_example.txt"os.rename(file_path,new_file_path)print("File renamed.")

Output:

File renamed.

Lists the files found within a directory

importos# List files in a directorydirectory_path="example_directory"files=os.listdir(path=directory_path)print("Files in directory:",files)

Output:

Files in directory: ['example.txt']

Deletes a directory as long as it is empty

importos# Remove a directorydirectory_path="example_directory"os.rmdir(path=directory_path)print("Directory removed.")

Output:

Directory removed.

Process Management

With theos module, you can interact with processes, including launching new processes, obtaining process IDs, and managing process attributes.

importos# Launch a new processos.system("ls -l")# Get the process ID of the current processpid=os.getpid()print("Process ID:",pid)# Get the parent process IDppid=os.getppid()print("Parent Process ID:",ppid)

Output:

total 96-rw-r--r--@ 1 tlayach  staff      0 Feb 26 00:03 example.txt

Environment Variables Manipulation

Theos module enables manipulation of environment variables, allowing you to retrieve, set, and unset environment variables.

importos# Get value of an environment variablepython_path=os.getenv("PYTHONPATH")print("PYTHONPATH:",python_path)# Set an environment variableos.environ["NEW_VARIABLE"]="new_value"print("NEW_VARIABLE set.")# Unset an environment variableos.environ.pop("NEW_VARIABLE",None)print("NEW_VARIABLE unset.")

Output:

PYTHONPATH: /Users/...NEW_VARIABLE set.NEW_VARIABLE unset.

Conclusion

Theos library in Python serves as a versatile toolkit for interacting with the operating system, empowering developers to perform a wide range of file and directory operations, manage processes, and manipulate environment variables seamlessly.