os.fdatasync(fd) 

# Python program to explain os.fdatasync() method 
    
# importing os module 
import os
  
  
# File path
path = 'file.txt'
  
# Open the file and get
# the file descriptor 
# associated with 
# using os.open() method
fd = os.open(path, os.O_RDWR)
  
  
# Write a bytestring
str = b"GeeksforGeeks" 
  
os.write(fd, str)
  
  
# The written string is
# available in program buffer
# but it might not actually 
# written to disk until
# program is closed or 
# file descriptor is closed. 
  
# sync. all internal buffers
# associated with the file descriptor
# with disk (force write of file)
# using os.fdatasync() method
os.fdatasync(fd)
print("Force write of file committed successfully")
  
# Close the file descriptor 
os.close(fd)
  
# os.fdatasync() method
# does not force update of
# metadata. if you want to 
# update it too, use
# os.fsync() method instead. 

Force write of file committed successfully