how to concisely create a temporary file that is a copy of another file in python

Question

I know that it is possible to create a temporary file, and write the data of the file I wish to copy to it. I was just wondering if there was a function like:

Answer 1

A variation on @tramdas's answer, accounting for the fact that the file cannot be opened twice on windows. This version ignores the preservation of the file extension.

import os, shutil, tempfile

def create_temporary_copy(src):
  # create the temporary file in read/write mode (r+)
  tf = tempfile.TemporaryFile(mode='r+b', prefix='__', suffix='.tmp')

  # on windows, we can't open the the file again, either manually
  # or indirectly via shutil.copy2, but we *can* copy
  # the file directly using file-like objects, which is what
  # TemporaryFile returns to us.
  # Use `with open` here to automatically close the source file
  with open(src,'r+b') as f:
    shutil.copyfileobj(f,tf)

  # display the name of the temporary file for diagnostic purposes
  print 'temp file:',tf.name

  # rewind the temporary file, otherwise things will go
  # tragically wrong on Windows
  tf.seek(0) 
  return tf

# make a temporary copy of the file 'foo.txt'
name = None

with create_temporary_copy('foo.txt') as temp:
  name = temp.name

  # prove that it exists
  print 'exists', os.path.isfile(name) # prints True

  # read all lines from the file
  i = 0
  for line in temp:
    print i,line.strip()
    i += 1

  # temp.close() is implicit using `with`

# prove that it has been deleted
print 'exists', os.path.isfile(name) # prints False