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Subject: Re: chunking a long string?
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From: Roy Smith <roy@panix.com>
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Date: Fri, 8 Nov 2013 13:24:40 -0500
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To: Nick Cash <nick.cash@npcinternational.com>
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Xref: csiph.com comp.lang.python:58836

Oh my, it turns out I don't really need to do this after all, due to =
previously undiscovered uber-coolness in the tools I'm using!

My use case is that from inside of a Django view, I needed to retrieve a =
large file via a HTTP GET, and serve that back up, with some time delays =
inserted into the data stream.  Turns out, requests (uber-cool tool #1) =
provides a way to iterate over the content of a GET, and Django =
(uber-cool tool #2) provides a way to build a HttpResponse from the data =
in an iterator.  Epiphany!  I ended up with (essentially) this:

def stream_slow(request, song_id):
    """Streams a song, but does it extra slowly, for client testing      =
                                                                      =20=

    purposes.                                                            =
                                                                      =20=

                                                                         =
                                                                         =
                                                                         =
                                                                    =20
    """
    def _slow_stream(r, chunk_size):
        for chunk in r.iter_content(chunk_size):
            yield chunk
            time.sleep(0.1)

    url =3D get_url(song_id)
    response =3D requests.get(url, stream=3DTrue)
    return HttpResponse(_slow_stream(response, 1024))




On Nov 8, 2013, at 12:59 PM, Nick Cash wrote:

>> I have a long string (several Mbytes).  I want to iterate over it in =
manageable chunks
>=20
> This is a weirdly common question. See =
http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-eve=
nly-sized-chunks-in-python for several solutions.
>=20
> It's been proposed to be added to itertools before, but rejected: =
https://mail.python.org/pipermail/python-ideas/2012-July/015671.html and =
http://bugs.python.org/issue13095=20
>=20
> - Nick Cash=20
>=20


---
Roy Smith
roy@panix.com