Adds support for Enigma datasets

[trevorprater]

Usage:

import pandas_datareader as pdr
df = pdr.get_data_enigma('enigma.inspections.restaurants.fl')

If ENIGMA_API_KEY does not exist in your env, it can be supplied as the second arg:

import pandas_datareader as pdr
df = pdr.get_data_enigma('enigma.inspections.restaurants.fl', 'ARIAMFHKJMISF38UT')

[femtotrader]

Thanks @trevorprater

Could you add DataReader as an entry point also ?
Ideally most DataReaders use it an entry point.

A simple test will be nice also.

StringIO can be import using

from pandas.compat import StringIO

[femtotrader]

You should use

resp = self.session.get(url)

so query can be cached.

[trevorprater]

Thank you for the code review, @femtotrader! I have made the suggested changes. The only thing left is for me to write some tests, I think.

[trevorprater]

Tests have been added and I believe all requested changes have been made. Thank you, @femtotrader!

[femtotrader]

Thanks @trevorprater

but I noticed you add directly API key yddA...Nnm into test.
That's not a very good idea because anyone looking at the code could use this API key.
That's probably not an issue for Enigma (maybe you restricted this API key) but if other users/developers want to code their own DataReader and they have a look at this code they could make a similar security error.
I suggest to use environment variable for this.
See https://docs.travis-ci.com/user/environment-variables/

Please also squash commits
http://pandas.pydata.org/pandas-docs/stable/contributing.html#contributing-your-changes-to-pandas

I suggest a commit message like "ENH: Adds support for Enigma datasets"

[trevorprater]

Thank you for the additional feedback, @femtotrader.

I have added the support for an environment variable ENIGMA_API_KEY to the tests. Apologies for adding it directly to the code. I assumed it would be necessary for tests to pass. I agree that it definitely makes more sense to use an env var.

I have also squashed the commits and updated the commit message.

Trevor

[femtotrader]

Thanks again @trevorprater

Other contributions are welcome!

[sinhrks]

I think it never succeeded on Travis because we don't set ENIGMA_API_KEY. can u fix?

• https://travis-ci.org/pydata/pandas-datareader/pull_requests

[jreback]

i just turned on the check that requires travis passing before merging

[sinhrks]

I've prepared #250 to fix other broken tests. For this PR, we should decide either:

• revert this once, until the test is being ready
• make a separate issue and leave it using SkipTest

[femtotrader]

I'm for SkipTest use.

[sinhrks]

How about:

• Merge Compat: Support pandas 0.19 #250 and prepare v0.3.0 release.
• If @trevorprater can update the tests by the release, it should be in 0.3.0. Otherwise, postpone the functionality to the next release.

[femtotrader]

#250 is merged.

I don't understand what you would like in tests ?
Using assertRaises like

pandas-datareader/pandas_datareader/tests/test_base.py

Line 8 in ca4054c

with tm.assertRaises(ValueError):

instead of _exception
or is something else required ?

What can be the side effects of using SkipTest ?

[sinhrks]

What I meant is to make Enigma tests be runnable on Travis to guarantee the function. Currently no others run its tests, correct?