BUG: using a list in "selector" for set_table_styles produces wrong rules

[levitsky]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• (optional) I have confirmed this bug exists on the master branch of pandas.

---

Problem description

Example: I want to apply a style like this:

df.style.set_table_styles([{'selector': 'th.col_heading,th.blank', 'props': [('display', 'none')]}])

Note a list (th.col_heading,th.blank) as selector. This produces wrong CSS, because UUID of the table is only prepended once to this selector:

#T_table_UUID th.col_heading, th.blank {
      display: none;
}

i.e. all th.blank elements in all tables on the page are hidden. This is not exactly intuitive, although the workaround is simple: you need to write

set_table_styles([{'selector': 'th.col_heading', 'props': [('display', 'none')]}, {'selector': 'th.blank', 'props': [('display', 'none')]}])

INSTALLED VERSIONS

commit : None
python : 3.8.2.final.0
python-bits : 64
OS : Linux
OS-release : 5.6.10-arch1-1
machine : x86_64
processor :
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8

pandas : 1.0.3
numpy : 1.18.4
pytz : 2020.1
dateutil : 2.8.1
pip : 20.0.2
setuptools : 46.1.3
Cython : None
pytest : 5.4.1
hypothesis : None
sphinx : 3.0.3
blosc : None
feather : None
xlsxwriter : None
lxml.etree : 4.5.0
html5lib : 1.0.1
pymysql : None
psycopg2 : None
jinja2 : 2.11.2
IPython : 7.14.0
pandas_datareader: None
bs4 : 4.9.0
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : 4.5.0
matplotlib : 3.2.1
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pytables : None
pytest : 5.4.1
pyxlsb : None
s3fs : None
scipy : 1.4.1
sqlalchemy : 1.3.16
tables : None
tabulate : None
xarray : None
xlrd : 1.2.0
xlwt : None
xlsxwriter : None
numba : None

[TomAugspurger]

@levitsky Thanks for the report. can you provide a minimal exmaple? http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports

[levitsky]

It's enough to create an empty DataFrame and apply the style above, then render the resulting HTML:

import pandas as pd
df = pd.DataFrame()
df.style.set_table_styles([{'selector': 'th.col_heading,th.blank', 'props': [('display', 'none')]}]).render()

The resulting HTML is something like this:

<style  type="text/css" >
    #T_cd059770_eed6_11ea_b183_645a04675490 th.col_heading,th.blank {
          display: none;
    }</style><table id="T_cd059770_eed6_11ea_b183_645a04675490" ><thead></thead><tbody>
        </tbody></table>

As you can see, the rule #T_cd059770_eed6_11ea_b183_645a04675490 th.col_heading,th.blank will lead to unexpected results in case the page containing this code also has other tables, because the th.blank part will apply universally rather than just the current DataFrame.

I think this can be addressed by parsing the selector passed to set_table_styles (to produce the correct rule, or at least throw a warning/exception) or maybe at least documenting this limitation.