how do i get the byte count of a variable in python just like wc -c gives in unix

i am facing some problem with files with huge data. i need to skip doing some execution on those f开发者_开发百科iles. i get the data of the file into a variable. now i need to get the byte of the variable and if it is greater than 102400 , then print a message.

update : i cannot open the files , since it is present in a tar file. the content is already getting copied to a variable called 'data' i am able to print contents of the variable data. i just need to check if it has more than 102400 bytes.

thanks

import os
length_in_bytes = os.stat('file.txt').st_size
if length_in_bytes > 102400:
   print 'Its a big file!'

Update to work on files in a tarfile

import tarfile
tf = tarfile.TarFile('foo.tar')
for member in tarfile.getmembers():
    if member.size > 102400:
        print 'It's a big file in a tarfile - the file is called %s!' % member.name

Just check the length of the string, then:

if len(data) > 102400:
  print "Skipping file which is too large, at %d bytes" % len(data)
else:
  process(data) # The normal processing

If I'm understanding the question correctly, you want to skip certain input files if they're too large. For that, you can use os.path.getsize():

import os.path
if os.path.getsize('f') <= 102400:
  doit();

len(data) gives you the size in bytes if it's binary data. With strings the size depends on the encoding used.

This answer seems irrelevant, since I seem to have misunderstood the question, which has now been clarified. However, should someone find this question, while searching with pretty much the same terms, this answer may still be relevant:

Just open the file in binary mode

f = open(filename, 'rb')

read/skip a bunch and print the next byte(s). I used the same method to 'fix' the n-th byte in a zillion images once.