How to edit a file to increase the size by adding white spaces at end in python

Question

I want to first create a copy of a file and then check the size of the file and if the size is less than 1 MB then add white spaces at end of the file to make it 1 MB size.

I have copied the using below code but I am getting any help for adding white spaces at end of the file.

from shutil import copyfile
copyfile(self.actualfile,self.copyfile)

Answer 1

you can do it like this:

import os

filename = 'file.txt'

size = os.stat(filename).st_size

f = open(filename, "a+")
f.write(" " * (1024*1024 - size))
f.close();

Answer 2

This uses pathlib from newer Pythons to simplify getting the file's size and adding exactly the padding you want.

#!/usr/bin/env python

import pathlib
import shutil

destfile = pathlib.Path("/tmp/foo")
shutil.copyfile(__file__, destfile)

required_padding = 1024 * 1024 - destfile.stat().st_size
if required_padding > 0:
    with destfile.open("ab") as outfile:
        outfile.write(b" " * required_padding)

Answer 3

with open(self.actualfile, 'r') as fin: with open(self.copyfile, 'w') as fout: print('{:<1048756}'.format(fin.read()), file=fout)

Answer 4

You can try this:

actual_size = os.path.getsize(self.copyfile)
    x = " " * (int(size)-actual_size)
    with open(self.copyfile, "a", encoding="utf-8") as f:
        f.write(x)      
    print("Size (In bytes) of '%s':" %os.path.getsize(self.copyfile))