[atlas] Introducing: the new result parsing library (Sagan)

On Mon, May 12, 2014 at 12:10:01PM +0200,
 dquinn <dquinn at ripe.net> wrote 
 a message of 28 lines which said:

> The idea is that you run every result you get through this handy
> Python library and out comes programmer-friendly Python objects. It
> supports the various changes in result format over time, and even
> does some of the heavy lifting for you like calculating ping median
> rtt, parsing the DNS abuf, or counting the traceroute hops.

Unfortunately, it seems it have been made for brains brighter than
mine. I tried the following script:

import sys

from ripe.atlas.sagan import PingResult

if len(sys.argv) <= 1:
    raise Exception("Usage: %s filename ..." % sys.argv[0])

for filename in sys.argv[1:]:
    results = open(filename).read()
    result = PingResult(results)
    print filename
    print result.rtt_median
    print ""

And I give it the result of a measurement (#1666654 if you want to
check):

Traceback (most recent call last):
  File "sagan-ping.py", line 19, in <module>
    result = PingResult(results)
  File "/usr/local/lib/python2.7/dist-packages/ripe.atlas.sagan-0.1.14-py2.7.egg/ripe/atlas/sagan/ping.py", line 54, in __init__
    Result.__init__(self, data, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/ripe.atlas.sagan-0.1.14-py2.7.egg/ripe/atlas/sagan/base.py", line 118, in __init__
    "measurement: {raw_data}".format(raw_data=self.raw_data))
ripe.atlas.sagan.base.ResultParseError: This does not look like a RIPE
Atlas measurement: [{u'af': 6, u'prb_id': 10031, u'result': [{u'rtt':
56.194}, {u'rtt': 54.074}, {u'rtt': 54.47}], u'ttl': 54, u'avg':
54.9126666667, u'size': 48, u'from':
u'2a01:1e8:e13f:0:a2f3:c1ff:fec4:5fab', u'proto': u'ICMP',
u'timestamp': 1401114806, u'dup': 0, u'type': u'ping', u'sent': 3,
u'msm_id': 1666654, u'fw': 4610, u'max': 56.194, u'step': None,
u'src_addr': u'2a01:1e8:e13f:0:a2f3:c1ff:fec4:5fab', u'rcvd': 3,
u'msm_name': u'Ping', u'lts': 16, u'dst_name':
u'2001:4b98:dc0:41:216:3eff:fece:1902', u'min': 54.074, u'group_id':
1666654, u'dst_addr': u'2001:4b98:dc0 [...]

The JSON file (attached) does seem correct.

I also tried with pre-parsing:

for filename in sys.argv[1:]:
    results = json.loads(open(filename).read())
    result = PingResult(results)
    print filename

and got the same result.