DOC: Validation errors on doctests with output too long for a single line

[mpmoran]

RE: PR #27280

Multiple docstring tests are failing because of pretty whitespace formatting of the expected output. Here is an example from read_json() in pandas/io/json/_json.py:500

Encoding/decoding a Dataframe using ``'split'`` formatted JSON:

>>> df.to_json(orient='split')
'{"columns":["col 1","col 2"],
  "index":["row 1","row 2"],
  "data":[["a","b"],["c","d"]]}'

Running the validation script results in the following error:

Line 153, in pandas.read_json
Failed example:
    df.to_json(orient='split')
Expected:
    '{"columns":["col 1","col 2"],
      "index":["row 1","row 2"],
      "data":[["a","b"],["c","d"]]}'
Got:
    '{"columns":["col 1","col 2"],"index":["row 1","row 2"],"data":[["a","b"],["c","d"]]}'

There is another similarly failing example in this function's doctests. Series.to_json has similar failures as well.

The +NORMALIZE_WHITESPACE directive does not help and neither do ellipses. Removing the whitespace does cure the failures, but it looks nasty.

INSTALLED VERSIONS ------------------ commit : c64c9cb python : 3.7.3.final.0 python-bits : 64 OS : Darwin OS-release : 18.6.0 machine : x86_64 processor : i386 byteorder : little LC_ALL : None LANG : en_US.UTF-8 LOCALE : en_US.UTF-8

pandas : 0.25.0rc0+23.gc64c9cb44
numpy : 1.16.4
pytz : 2019.1
dateutil : 2.8.0
pip : 19.1.1
setuptools : 41.0.1
Cython : 0.29.11
pytest : 5.0.0
hypothesis : 4.23.6
sphinx : 1.8.5
blosc : None
feather : None
xlsxwriter : 1.1.8
lxml.etree : 4.3.4
html5lib : 1.0.1
pymysql : None
psycopg2 : None
jinja2 : 2.10.1
IPython : 7.6.0
pandas_datareader: None
bs4 : 4.7.1
bottleneck : 1.2.1
fastparquet : 0.3.0
gcsfs : None
lxml.etree : 4.3.4
matplotlib : 3.1.0
numexpr : 2.6.9
odfpy : None
openpyxl : 2.6.2
pandas_gbq : None
pyarrow : 0.11.1
pytables : None
s3fs : 0.2.1
scipy : 1.2.1
sqlalchemy : 1.3.5
tables : 3.5.2
xarray : 0.12.1
xlrd : 1.2.0
xlwt : 1.3.0
xlsxwriter : 1.1.8

[mpmoran]

See https://stackoverflow.com/questions/17640416/doctest-normalize-whitespace-does-not-work. It does appear that to_json returns an str without any whitespace between the commas and this is why NORMALIZE_WHITESPACE doesn't work. A few ideas off the top of my head are wrapping the calls in pprint or adding a feature to to_json to allow for pretty output.

If y'all have any ideas as to how to fix this, I would be willing to take a crack at 'em.