Understanding tempfile.TemporaryFile

[Brad]

Wondering if someone would help me to better understand tempfile. I 
attempt to create a tempfile, write to it, read it, but it is not 
behaving as I expect. Any tips?

 >>> x = tempfile.TemporaryFile()
 >>> print x
<open file '<fdopen>', mode 'w+b' at 0xab364968>
 >>> print x.read()

 >>> print len(x.read())
0
 >>> x.write("1234")
 >>> print len(x.read())
0
 >>> x.flush()
 >>> print len(x.read())
0