Python os.fdopen() Method
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Syntax of Python
os.fdopen()Method -
Example 1: Use the
os.fdopen()Method in Python -
Example 2: Read the File After Using the
os.fdopen()Method -
Example 3: Use the
os.fdopenMethod With theos.open()Method
Python os.fdopen() method returns an open file object connected to the fd file descriptor. It is an alias of the os.open() method.
Both methods don’t have a difference in their working except that the os.fdopen() method’s first argument should be an integer.
Syntax of Python os.fdopen() Method
os.fdopen(fd, mode)
Parameters
fd |
It is a file descriptor for which a file object is needed to open. |
mode |
It is an optional parameter representing the mode of the newly opened file. The default value of the mode is an octal numeric integer 0o777. |
The most used values of the mode parameter are r for reading a file, w for writing/truncating a file, and a for appending the file. |
Return
This method returns the newly opened file’s path connected to the file descriptor.
Example 1: Use the os.fdopen() Method in Python
import os
import sys
fd = os.open("foo.txt", os.O_RDWR | os.O_CREAT)
file = os.fdopen(fd, "w+")
file.write("Hello, World!")
file.close()
print("File created successfully.")
Output:
File created successfully.
While using the os.fdopen() method, we can use one or more modes simultaneously by using the vertical bar |.
Example 2: Read the File After Using the os.fdopen() Method
import os
path_address = "./File.txt"
mode_set = 0o666
flags = os.O_CREAT | os.O_RDWR
descriptor = os.open(path_address, flags, mode_set)
file = os.fdopen(descriptor, "w+")
print("The new file has been created.")
line = "Hello, World! Programming is fun!"
os.write(descriptor, line.encode())
print("The text has been successfully entered into the file.")
file.close()
print("The file descriptor has been closed successfully.")
Output:
The new file has been created.
The text has been successfully entered into the file.
The file descriptor has been closed successfully.
It is a healthy practice for any programmer to close all the newly opened files using the os.close() method.
Example 3: Use the os.fdopen Method With the os.open() Method
import os
with os.fdopen(os.open("File.txt", os.O_CREAT | os.O_RDWR), "w") as fd:
fd.write("Hello, World!")
print("The file descriptor has been closed successfully.")
Output:
The file descriptor has been closed successfully.
Note that the returned file descriptor from this method is non-inheritable.
Musfirah is a student of computer science from the best university in Pakistan. She has a knack for programming and everything related. She is a tech geek who loves to help people as much as possible.
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