Using temporary file as backing object for a tarfile

Question

I have existing code that handles a tarball and would like to use that to process a directory, so I thought it would be reasonable to pack the directory up in a temporary file. I ended up writing:

class temp_tarball( object ):
 def __init__( self, path ):
 self.tmp = tempfile.NamedTemporaryFile()
 self.tarfile = tarfile.open( None, 'w:', self.tmp )
 self.tarfile.add( path, '.' )
 self.tarfile.close()
 self.tmp.flush()
 self.tarfile = tarfile.open( self.tmp.name, 'r:' )
 def __del__( self ):
 self.tarfile.close()
 self.tmp.close()

I am looking for a cleaner way to reopen the tarfile with mode 'r'.

• Winston Ewert: What's your concern with it now?
• William Pursell: @winston I don't like using the NamedTemporaryFile, and would prefer to use tempfile.TemporaryFile. I don't really have a specific complaint; it just smells a bit funny as it is.

Answer 1

You could try:

def __init__(self, path):
 self.tmp = tempfile.TemporaryFile()
 self.tarfile = tarfile.open( fileobj=self.tmp, mode='w:' )
 self.tarfile.add( path, '.' )
 self.tarfile.close()
 self.tmp.flush()
 self.tmp.seek(0)
 self.tarfile = tarfile.open( fileobj=self.tmp, mode='r:' )

tarfile() will take a fileobj in the constructor instead of a name, so as long as you don't close it, and instead just seek() to 0 when you want to re-read it, you should be good.