Python and audit support

[rushter]

Hi,

Is there a way to get audit results as a string?

I found the audit_example method, but it outputs to stdout.

import vowpalwabbit.pyvw
model = vowpalwabbit.pyvw.vw('-t -i model.vw --json --audit')
example = model.parse(example_as_str)
ouput = model.audit_example(example)

I see that audit is mentioned in Python docstrings, but there are no examples or documentation on how to retrieve results.

        """Initialize the vw object.

        Parameters
        ----------

        arg_str : str
            The command line arguments to initialize VW with,
            for example "--audit". By default is None.

[jackgerrits]

There is not currently a way to do this unfortunately. However, it is clearly highly valuable and something I think we should do.

[lalo]

This could be achievable with the following bits:

• Avoiding the std:cout

  vowpal_wabbit/vowpalwabbit/gd.cc

  Line 305 in 4ccc760

  for (string_value& sv : dat.results) std::cout << '\t' << sv.s;

• instantiating vw with enable_logging=True
  

  vowpal_wabbit/python/tests/test_cb.py

  Line 41 in 4ccc760

  vw = pyvw.vw("--cb 4", enable_logging=True)

• and then calling output = vw.get_log()

[priyanshuone6]

Hi, doing

from vowpalwabbit import pyvw
model = pyvw.vw('--audit')
ex = model.parse("0:0.1:0.75 | a:0.5 b:1 c:2")
output = model.audit_example(ex)

gives me a:92594:0.5:0@0 b:163331:1:0@0 c:185951:2:0@0 Constant:116060:1:0@0 as stdout which does not store it as a string. So I tried adding what @lalo suggested and model.get_log() gives me

['Num weight bits = 18\n',
 'learning rate = 0.5\n',
 'initial_t = 0\n',
 'power_t = 0.5\n',
 'using no cache\n',
 'Reading datafile = \n',
 'num sources = 1\n',
 'Enabled reductions: gd, scorer\n',
 'average  since         example        example  current  current  current\n',
 'loss     last          counter         weight    label  predict features\n']

while this output doesn't match
@bassmang @jackgerrits

[jackgerrits]

Eduardo pointed out that with some work it may be accessible from the logs. However, as it is right now audit only goes to stdout. This is a feature request to make it accessible from Python.