Add \midrule Every 5 Lines Automatically

Question

I wrote a table listing scores of 40 students using booktabs package. How to write midrule command automatically every 5 rows?

\documentclass{article}
\usepackage{booktabs}
\begin{document}
\begin{table}[h]
\centering
\begin{tabular}{rclc}
\toprule
Number  & Student Id    & Name  & Score \\
\midrule % adding automatically
1       & 14-001    & Andy  & 75 \\
2       &           &       &    \\
3       &           &       &    \\
4       &           &       &    \\
5       &           &       &    \\  
\midrule % adding automatically
6       &           &       &    \\
7       &           &       &    \\
8       &           &       &    \\
9       &           &       &    \\
10      &           &       &    \\
\midrule % adding automatically
11      &           &       &    \\
\bottomrule
\end{tabular}
\caption{A List of Student Scores}
\label{}
\end{table}
\end{document}

Answer 1

Here's an option using the pgfplotstable package.

The idea is to read the data into a macro (called edytable below) and then typeset it using the command

    \pgfplotstabletypeset[
        columns/Student Id/.style={string type},
        columns/Name/.style={string type},
        every head row/.style={
            before row={%
                \toprule
            },
            after row=\midrule},
        every last row/.style={after row=\bottomrule},
        every nth row={5}{before row=\midrule},
    ]{\edytable}

The particularly relevant part to your question is the line

        every nth row={5}{before row=\midrule},

which instructs pgfplotstable to insert a \midrule on every 5th row.

% arara: pdflatex
% !arara: indent: {overwrite: yes}
\documentclass{article}
\usepackage{pgfplotstable}
\usepackage{booktabs}
\begin{document}

\pgfplotstableread[col sep = &, row sep = \\]{%
        Number  & Student Id    & Name  & Score \\
        1       & 14-001    & Andy  & 75 \\
        2       &           &       &    \\
        3       &           &       &    \\
        4       &           &       &    \\
        5       &           &       &    \\  
        6       &           &       &    \\
        7       &           &       &    \\
        8       &           &       &    \\
        9       &           &       &    \\
        10      &           &       &    \\
        11      &           &       &    \\
        }\edytable
    \pgfplotstabletypeset[
        columns/Student Id/.style={string type},
        columns/Name/.style={string type},
        every head row/.style={
            before row={%
                \toprule
            },
            after row=\midrule},
        every last row/.style={after row=\bottomrule},
        every nth row={5}{before row=\midrule},
    ]{\edytable}

\end{document}

There are lots of different ways that you could read in the data into edytable - I used col sep = &, row sep =\\ simply because that used the code available.

Answer 2

The following macro \midruleV sets a \midrule every five rows. Counter midruleV is used to count the rows inside a block of five rows. Therefore the counter is reset before the table and after the header, because the header does not count.

The larger problem is finding a place to put \midruleV. The example puts it after the last cell by escaping the current group twice. Therefore the rows should not end early by omitting cells.

Before the end of the last row \vadjust{\resetmidruleV} prevents that the rule is inserted after a multiple of five rows and the table closes with \midrule and \bottomrule.

\documentclass{article}
\usepackage{array}
\usepackage{booktabs}

\newcounter{midruleV}
\newcommand*{\midruleV}{%
  \aftergroup\aftergroup\aftergroup\midruleVaux
}
\newif\ifmidruleV
\makeatletter
\newcommand*{\midruleVaux}{%
  \noalign{%
    \stepcounter{midruleV}%
    \ifnum\value{midruleV}=5 %
      \global\midruleVtrue
      \setcounter{midruleV}{0}%
    \else
      \global\midruleVfalse
    \fi
  }
  \ifmidruleV\midrule\fi
}
\newcommand*{\resetmidruleV}{\setcounter{midruleV}{0}}
\makeatother

\begin{document}
\begin{table}[h]
\centering
\resetmidruleV
\begin{tabular}{rclc<{\midruleV}}
\toprule
Number  & Student Id    & Name  & Score \\
\noalign{\resetmidruleV}%
\midrule % adding automatically
1       & 14-001    & Andy  & 75 \\
2       &           &       &    \\
3       &           &       &    \\
4       &           &       &    \\
5       &           &       &    \\  
6       &           &       &    \\
7       &           &       &    \\
%8       &           &       &    \\
9       &           &       &    \\
10      &           &       &    \\
11      &           &       &    \vadjust{\resetmidruleV}\\
\bottomrule
\end{tabular}
\caption{A List of Student Scores}
\label{}
\end{table}
\end{document}