When I'm using the pandas.to_latex function to create latex table, the column names are unfortunately not bold. What can I do to make it bold?

CodePudding user response：

Here is a complete example, this is adapted from the offical documentation.

There is a keyword to print bold columns bold_rows=True. Sadly there isn't a kyword parameter to do the same for the columns. But I can use this to check if my code gives the same result for the column headers.

I use the result of to_latex() and split it in three sections. One section is the line with the column names. In this line I use a regular expression to add the \text{}-string. My code works only if you colum names don't have a whitespace.

import pandas as pd

df = pd.DataFrame(
    dict(name=['Raphael', 'Donatello'],
         mask=['red', 'purple'],
         weapon=['sai', 'bo staff']
        )
)
ans = df.to_latex(bold_rows=True)

split_middle = '\n\midrule\n'
split_top = '\\toprule\n'
top, mid = ans.split(split_middle)
start, columns = top.split(split_top)

columns = re.sub('(\w) ', '\\\\textbf{\g<0>}', columns)

result = split_middle.join([split_top.join([start, columns]), mid])
>>> result
\begin{tabular}{llll}
\toprule
{} &       \textbf{name} &    \textbf{mask} &    \textbf{weapon} \\
\midrule
\textbf{0} &    Raphael &     red &       sai \\
\textbf{1} &  Donatello &  purple &  bo staff \\
\bottomrule
\end{tabular}

In the output you can see, that the header now is bold.

CodePudding user response：

Based on mosc9575's intuition to manipulate output of df.to_latex, you can make column header is wrapped with some unique delimiters to make the substitution easier.

import re

s = re.sub('<([^>]*)>', '\\\\textbf{\g<1>}',
           df.rename(columns=lambda x: f'<{x}>').to_latex(index=False))

\begin{tabular}{lll}
\toprule
   \textbf{name} & \textbf{mask} & \textbf{weapon} \\
\midrule
  Raphael &    red &      sai \\
Donatello & purple & bo staff \\
\bottomrule
\end{tabular}