rangereq.py

"""Source: http://stackoverflow.com/questions/1971240/python-seek-on-remote-file"""
import urllib2

class RangeError(Exception):
  pass

class HTTPRangeHandler(urllib2.BaseHandler):
  """Handler that enables HTTP Range headers.

This was extremely simple. The Range header is a HTTP feature to
begin with so all this class does is tell urllib2 that the 
"206 Partial Content" reponse from the HTTP server is what we 
expected.

Example:
    import urllib2
    import byterange

    range_handler = range.HTTPRangeHandler()
    opener = urllib2.build_opener(range_handler)

    # install it
    urllib2.install_opener(opener)

    # create Request and set Range header
    req = urllib2.Request('http://www.python.org/')
    req.header['Range'] = 'bytes=30-50'
    f = urllib2.urlopen(req)
"""
  def http_error_206(self, req, fp, code, msg, hdrs):
    # 206 Partial Content Response
    r = urllib.addinfourl(fp, hdrs, req.get_full_url())
    r.code = code
    r.msg = msg
    return r

  def http_error_416(self, req, fp, code, msg, hdrs):
    # HTTP's Range Not Satisfiable error
    raise RangeError('Requested Range Not Satisfiable')


range_handler = HTTPRangeHandler()
opener = urllib2.build_opener(range_handler)

# install it
urllib2.install_opener(opener)