python tempfile: how to open several times the temp file?

Question

I am trying to use the tempfile module. (http://docs.python.org/2.7/library/tempfile.html) I am looking for a temporary file that I could open several times to get several streams to read it.

tmp = ...
stream1 = # get a stream for the temp file
stream2 = # get another stream for the temp file

I have tried several functions (TemporaryFile, NamedTemporaryFile, SpooledTemporaryFile) and using the fileno method or so but I could not perform what I am looking for.

Any idea of should I just make my own class?

Thanks

> UPDATE

I get an error trying to open the file with its name...

In [2]: t = tempfile.NamedTemporaryFile()
In [3]: t.write('abcdef'*1000000)
In [4]: t.name
Out[4]: 'c:\\users\\mike\\appdata\\local\\temp\\tmpczggbt'
In [5]: f = open(t.name)
---------------------------------------------------------------------------
IOError                                   Traceback (most recent call last)
<ipython-input-6-03b9332531d2> in <module>()
----> 1 f = open(t.name)

IOError: [Errno 13] Permission denied: 'c:\\users\\mike\\appdata\\local\\temp\\tmpczggbt'

Answer 1

File objects (be they temporary or otherwise) cannot be read multiple times without re-positioning the file position back to the start.

Your options are:

• To reopen the file multiple times, creating multiple file objects for the same file.
• To rewind the file object before each read.

To reopen the file, use a NamedTemporaryFile and use a regular open() call to re-open the same filename several times. You probably will want to pass delete=False to the constructor, especially on Windows, to be able to do this.

To rewind, call .seek(0) on the file object.