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StringIO.readline() returns ''

Max
I'm using StringIO for the first time (to buffer messages recieved from
a socket). I thought it would be a simple matter of writing the stuff to
the buffer and then calling readline, but that doesn't seem to work:
buf = StringIO.StringIO()
buf.write("Foo\n")
buf.write("Bar\n")
buf.flush()
buf.readline()

''

I expected buf.readline() to return 'Foo\n'. What am I doing wrong?

--Max
Apr 9 '06 #1
3 7129
"Unknown" wrote:
I'm using StringIO for the first time (to buffer messages recieved from
a socket). I thought it would be a simple matter of writing the stuff to
the buffer and then calling readline, but that doesn't seem to work:
>>> buf = StringIO.StringIO()
>>> buf.write("Foo\n")
>>> buf.write("Bar\n")
>>> buf.flush()
>>> buf.readline() ''

I expected buf.readline() to return 'Foo\n'. What am I doing wrong?


you forgot to rewind the file:
buf = StringIO.StringIO()
buf.write("Foo\n")
buf.write("Bar\n")
buf.seek(0)
buf.readline()

'Foo\n'

</F>

Apr 9 '06 #2
Max
Fredrik Lundh wrote:
you forgot to rewind the file:

Thank you.

</F>


--Max
Apr 9 '06 #3
You can also just type buf.getvalue() which returns the current
StringIO buffer as a python string, without the rewinding

Apr 10 '06 #4

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