The os module

The os module is Python's door to the operating system: the working directory, the filesystem layout, and the environment. This node covers the path and directory helpers you'll reach for constantly.

import os

Where am I

os.getcwd() returns the current working directory as a string:

os.getcwd()   # '/root/project'

Listing and creating directories

os.listdir(path) returns the names in a directory as a list. os.makedirs(path) creates a directory, including any missing parents:

os.listdir("/root")            # ['project', 'answers', ...]
os.makedirs("/root/logs/app")  # creates logs and logs/app

Pass exist_ok=True to makedirs so it doesn't error when the folder is already there:

os.makedirs("/root/logs", exist_ok=True)

Building and inspecting paths

os.path.join joins path pieces with the right separator, which is safer than gluing strings with slashes:

os.path.join("/root", "logs", "app.log")   # '/root/logs/app.log'

os.path.exists(path) tells you whether a path is there, and os.path.basename and os.path.dirname split a path into its file name and its folder:

os.path.exists("/root/logs")            # True
os.path.basename("/root/logs/app.log")  # 'app.log'
os.path.dirname("/root/logs/app.log")   # '/root/logs'

What this node introduces

• os.getcwd() returns the current directory.
• os.listdir(path) lists a directory; os.makedirs(path) creates one.
• os.path.join, os.path.exists, os.path.basename, and os.path.dirname build and inspect paths.