Python | os.path.join() method

OS module in Python provides functions for interacting with the operating system. OS comes under Python’s standard utility modules. This module provides a portable way of using operating system dependent functionality. os.path module is sub-module of OS module in Python used for common pathname manipulation.
os.path.join() method in Python join one or more path components intelligently. This method concatenates various path components with exactly one directory separator (‘/’) following each non-empty part except the last path component. If the last path component to be joined is empty then a directory separator (‘/’) is put at the end. 
If a path component represents an absolute path, then all previous components joined are discarded and joining continues from the absolute path component.

Syntax: os.path.join(path, *paths) 
Parameter:
path: A path-like object representing a file system path. 
*path: A path-like object representing a file system path. It represents the path components to be joined. 
A path-like object is either a string or bytes object representing a path.
Note: The special syntax *args (here *paths) in function definitions in python is used to pass a variable number of arguments to a function. 
Return Type: This method returns a string which represents the concatenated path components. 

Code: Use of os.path.join() method to join various path components 

Python3

# Python program to explain os.path.join() method

# importing os module
import os

# Path
path = "/home"

# Join various path components
print(os.path.join(path, "User/Desktop", "file.txt"))


# Path
path = "User/Documents"

# Join various path components
print(os.path.join(path, "/home", "file.txt"))

# In above example '/home'
# represents an absolute path
# so all previous components i.e User / Documents
# are thrown away and joining continues
# from the absolute path component i.e / home.


# Path
path = "/User"

# Join various path components
print(os.path.join(path, "Downloads", "file.txt", "/home"))

# In above example '/User' and '/home'
# both represents an absolute path
# but '/home' is the last value
# so all previous components before '/home'
# will be discarded and joining will
# continue from '/home'

# Path
path = "/home"

# Join various path components
print(os.path.join(path, "User/Public/", "Documents", ""))

# In above example the last
# path component is empty
# so a directory separator ('/')
# will be put at the end
# along with the concatenated value

Output:

/home/User/Desktop/file.txt
/home/file.txt
/home
/home/User/Public/Documents/

Reference: https://docs.python.org/3/library/os.path.html