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Python | os.lseek () method

os.lseek () sets the current position of the file descriptor fd to the given position pos, which is modified in the how way.

  Syntax:  os.lseek (fd, pos, how)  Parameters:   fd:  This is the file descriptor on which seek is to be performed.  pos:  This is the position in the file with respect to given parameter  how . It can accept three values ​​which are 
  • os.SEEK_SET or 0, to set the position relative to the beginning of the file
  • os.SEEK_CUR or 1, to set the position relative to the current position
  • os.SEEK_END or 2, to set the position relative to the end of the file.

as: is a breakpoint in the file. It also takes three values, which

  • os.SEEK_SET or 0, to set a breakpoint at the beginning of the file
  • os.SEEK_CUR or 1, to set the checkpoint to the current position
  • os.SEEK_END or 2 , to set the anchor point to the end of the file.

Returned value: This method does not return any value.  Example # 1: Using os.lseek () to find a file from the beginning

# Python program to explain the os.lseek () method

 
# import of the os module

import os 

 
# path

path = `C: / Users / Rajnish /Desktop/testfile.txt`

 
# Open the file and get
# the file descriptor associated
# using the os.open () method

fd = os. < / code> open (path, os.O_RDWR | os.O_CREAT)

 
# Line to write

s = `Python.Engineering - A Computer Science portal`

  
# Convert string to bytes

line = str . encode (s)

 
# Write line to file
# associated with file
# fd descriptor
os.write (fd, line)

 
# Search file from beginning
 # using the os.lseek () method

os.lseek (fd, 0 , 0 )

 
# Read file

s = os.read (fd, 13 )

 
# Print line

print (s)

 
# Close the file descriptor
os.close (fd)

Exit :

 b`GeeksforGeeks` 

Example # 2:

Using os.lseek () to find a file from a specific position ui

# Python program to explain the os.lseek () method

 
# import of the os module

import os 

  
# path

path =   `C: / Users / Rajnish / Desktop / testfile.txt`

 
# Open the file and get
# file descriptor associated
# using os.open () method

fd = os. open (path, os. O_RDWR | os.O_CREAT)

 
# Write string

s = `GeeksforGeeks`

 
# Convert string to bytes

line = str . encode (s)

 
# Write line to file
# associated with the file
# descriptor fd
os.write (fd, line)

 

 
# Search for file after position & # 39; 2 & # 39;
# using the os.lseek () method

os.lseek (fd, 2 , 0 )

 
# Read file

s = os.read (fd, 11 )

 
# Print line

print (s)

 
# Close the file descriptor
os.close (fd)

Exit :

 b`eksforGeeks` 
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