["python","file","file-io","filesize","tarfile"]
Size of an open file object

Is there a way to find the size of a file object that is currently open? Specifically, I am working with the tarfile module to create tarfiles, but I don't want my tarfile to exceed a certain size. As far as I know, tarfile objects are file-like objects, so I imagine a generic solution would work.
Do this: # seek to the end of the open file, f f.seek(0, os.SEEK_END) # get the current file position in the stream # - this is the size of the open file, in bytes f.tell() f.tell() documentation is here: https://docs.python.org/3/library/io.html#io.IOBase.tell Full example in a Python interpeter: $ ls -la chardet-1.0.1.tgz -rwxr-xr-x 1 vinko vinko 179218 2008-10-20 17:49 chardet-1.0.1.tgz $ python Python 2.5.1 (r251:54863, Jul 31 2008, 22:53:39) [GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> f = open('chardet-1.0.1.tgz','rb') >>> f.seek(0, os.SEEK_END) >>> f.tell() 179218L Adding ChrisJY's idea to the example >>> import os >>> os.fstat(f.fileno()).st_size 179218L >>> Note: Based on the comments, f.seek(0, os.SEEK_END) is must before calling f.tell(), without which it would return a size of 0. The reason is that f.seek(0, os.SEEK_END) moves the file object's position to the end of the file.