ENH: to_json(index=False)

[Suor]

Code Sample, a copy-pastable example if possible

import pandas as pd

df = pd.DataFrame([[1,2,3],[4,5,6]], columns=['a','b','c'])
df.to_json(orient='split')
# '{"columns":["a","b","c"],"index":[0,1],"data":[[1,2,3],[4,5,6]]}'

Problem description

Useless index data increases dump size. Affects only orients 'split' and 'table'.

Expected Output

>>>  df.to_json(orient='split', index=False)
'{"columns":["a","b","c"],"data":[[1,2,3],[4,5,6]]}'

This resembles a bit how .to_csv(index=False) works.

Output of pd.show_versions()

INSTALLED VERSIONS ------------------ commit: None python: 2.7.13.final.0 python-bits: 64 OS: Linux OS-release: 4.10.0-28-generic machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: en_US.UTF-8 LOCALE: en_US.UTF-8

pandas: 0.20.3
pytest: 2.6.4
pip: 9.0.1
setuptools: 36.2.5
Cython: None
numpy: 1.13.1
scipy: 0.16.0
xarray: None
IPython: 5.4.1
sphinx: None
patsy: 0.4.1
dateutil: 2.6.1
pytz: 2017.2
blosc: None
bottleneck: None
tables: None
numexpr: 2.6.2
feather: None
matplotlib: None
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
sqlalchemy: None
pymysql: None
psycopg2: 2.6 (dt dec pq3 ext lo64)
jinja2: 2.7.3
s3fs: None
pandas_gbq: None
pandas_datareader: None

[jreback]

this would be ok. a pull-request to implement would needed from the community for this.

[mpenkov]

I've started looking into this.