Python os.closerange() Method

1. Syntax of the os.closerange() Method
2. Example 1: Working With the os.closerange() Method in Python
3. Example 2: Use an Equivalent of the os.closerange() Method in Python
4. Example 3: Standard Range of the os.closerange() Method in Python

Python os.closerange() method is an efficient way of closing all file descriptors from fd_low (inclusive) to fd_high (exclusive). Any errors from fd_low to fd_high while closing file descriptors are ignored.

Syntax of the os.closerange() Method

os.closerange(fd_low, fd_high)

Parameters

Return

In the execution process, this method does not return any value.

Example 1: Working With the os.closerange() Method in Python

import os

path1 = "file1.txt"
path2 = "file2.txt"
path3 = "file3.py"
path4 = "file4.csv"

fd1 = os.open(path1, os.O_WRONLY | os.O_CREAT)
fd2 = os.open(path2, os.O_WRONLY | os.O_CREAT)
fd3 = os.open(path3, os.O_WRONLY | os.O_CREAT)
fd4 = os.open(path4, os.O_WRONLY | os.O_CREAT)

string = "Hello, World!"

line = str.encode(string)

os.write(fd1, line)
os.write(fd2, line)
os.write(fd3, line)
os.write(fd4, line)

fd_low = min(fd1, fd2, fd3, fd4)
fd_high = max(fd1, fd2, fd3, fd4)
os.closerange(fd_low, fd_high + 1)
print("Closed all the files successfully!")

Output:

Closed all the files successfully!

A file descriptor fd is an abstract integer value that acts as a handle to perform various lower-level I/O operations such as read, write, send, etc.

Example 2: Use an Equivalent of the os.closerange() Method in Python

import os

fd = os.open( "file.txt", os.O_RDWR|os.O_CREAT )

string = "Hello, World!"

line = str.encode(string)

os.write(fd, line)

os.close(fd)

print ("Closed all the files successfully!")

Output:

Closed all the files successfully!

The os.closerange() is a more efficient method than os.close() because it allows flexibility in the file descriptors range.

Example 3: Standard Range of the os.closerange() Method in Python

import os

fd = os.open( "file.txt", os.O_RDWR|os.O_CREAT )

os.closerange( 0, 1)

print ("Closed all the files successfully!")

Output:

Closed all the files successfully!

The standard input is a file descriptor with value 0, whereas the standard output is a file descriptor with value 1. Moreover, the standard error is usually a file descriptor with a value of 2.