How to make pandas.style.to_latex() output header fields enclosed in {}?-CodePudding

I'm producing several LateX tables through python/pandas. Up until recently, the tables' headers were enclosed in {}, without any explicit instruction for that, ie:

\begin{tabular}{llrrr}
{} & {date} & {x} & {y} & {z} \\
{} & {(yyyy-mm-dd)} & {(s)} & {(m)} & {(kg)} \\
0 & 2014-03-12 & 1 & 2 & 3 \\
1 & 2014-03-13 & 4 & 5 & 6 \\
\end{tabular}

But recently, the output from pandas.style.to_latex() started being the following (without the {}):

\begin{tabular}{llrrr}
 & date & x & y & z \\
 & (yyyy-mm-dd) & (s) & (m) & (kg) \\
0 & 2014-03-12 & 1 & 2 & 3 \\
1 & 2014-03-13 & 4 & 5 & 6 \\
\end{tabular}

As I'm post-processing these LateX tables in python, I need the headers to be enclosed in {}

Does anyone know what I must do for that?

The original pandas dataframe can be generated through:

columns = pd.MultiIndex.from_tuples(
    zip(['date', 'x', 'y', 'z'],
        ['(yyyy-mm-dd)', '(s)', '(m)', '(kg)']))
data = [['2014-03-12', 1, 2, 3],
        ['2014-03-13', 4, 5, 6]]
df = pd.DataFrame(data, columns=columns)

CodePudding user response：

two ways,

df.style.to_latex(siunitx=True)

(since siunitx package requires this formatting)

df.style.format_index("{{{0}}}", axis=1).to_latex()

(explicitly using the format function to control the output)