Python | os.open() 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.open() method in Python is used to open a specified file path and set various flags according to the specified flags and its mode according to specified mode.
This method returns a file descriptor for newly open file. The returned file descriptor is non-inheritable.

Syntax: os.open(path, flags, mode = 0o777, *, dir_fd = None)

Parameters:
Path: A path-like object representing the file system path. This is the file path to be opened.
A path-like object is a string or bytes object which represents a path.
flags: This parameter specify the flags to be set for newly opened file.
mode (optional): A numeric value representing the mode of the newly opened file. The default value of this parameter is 0o777 (octal).
dir_fd (optional): A file descriptor referring to a directory.

Return Type: This method returns a file descriptor for newly opened file.

Code: Use of os.open() method to open a file path

# Python program to explain os.open() method

# importing os module
import os


# File path to be opened
path = './file9.txt'

# Mode to be set
mode = 0o666

# flags
flags = os.O_RDWR | os.O_CREAT


# Open the specified file path
# using os.open() method
# and get the file descriptor for
# opened file path
fd = os.open(path, flags, mode)

print("File path opened successfully.")


# Write a string to the file
# using file descriptor
str = "GeeksforGeeks: A computer science portal for geeks."
os.write(fd, str.encode())
print("String written to the file descriptor.")


# Now read the file
# from beginning
os.lseek(fd, 0, 0)
str = os.read(fd, os.path.getsize(fd))
print("\nString read from the file descriptor:")
print(str.decode())

# Close the file descriptor
os.close(fd)
print("\nFile descriptor closed successfully.")

Output:

File path opened successfully.
String written to the file descriptor.

String read from file descriptor:
GeeksforGeeks: A computer science portal for geeks.

File descriptor closed successfully.

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