为什么 csvsimple 不允许在第一行出现符号/数学？

Question

这软件包 csvsimple是一款不错的工具，可用于导入外部生成的大型表格。但是，它无法解释标头中带有符号或数学符号的文件。它不适用于 tabular 或 longtable 或任何其他 csvsimple 变体。为什么会这样，如何解决？

来自的问题csvsimple 导入的数学模式通过将“无头”作为选项来“解决”它，但是，嗯，没有头。

文件.csv：

a, $\delta$, \euro
b, c, x

Tex MWE：

\documentclass{book}
\usepackage[english]{babel}
\usepackage{csvsimple,longtable,booktabs}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{eurosym,textcomp} 
\begin{document}
% this fails:
\csvautotabular{file.csv}
% and this fails:
\csvreader[tabular=lll]{file.csv}{}{\csvcoli & \csvcolii & \csvcoliii}
\end{document}

错误：

! Missing \endcsname inserted.
<to be read again> 
                   \delta 
l.9 ...t.csv}{}{\csvcoli & \csvcolii & \csvcoliii}

Answer 1

如果不设置no head，则标题行的条目将用作列的宏名称。

如果它们包含空格或其他特殊字符，则它们不能用作可行的 LaTeX 宏名称，这就是出现错误的原因。

但是，您可以设置no head（或等效的head=false）并使用该选项late after first line将第一行视为标题。

编辑：通过一些过滤，您还可以管理longtable。

\documentclass{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[english]{babel}
\usepackage{caption}
\usepackage{csvsimple,longtable,booktabs}
\usepackage{eurosym,textcomp} 

% this code is only to create file.csv, you don't need it:
\usepackage{filecontents}
\begin{filecontents*}{file.csv}
a, $\delta$, \euro
b, c, x
d, e, y
f, g, z
\end{filecontents*}

\begin{filecontents*}{longfile.csv}
a, $\delta$, \euro
b, c, x
d, e, y
f, g, z
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
This, is, a
long, table, !
\end{filecontents*}

\begin{document}
\begin{table}[htb]
    \centering
    \caption{A short table}
    \csvreader[tabular=lll,
        head=false,
        table head=\toprule,
        late after line=\\,
        late after first line=\\\midrule,
        table foot=\bottomrule,
        ]{file.csv}{}{\csvcoli & \csvcolii & \csvcoliii}
\end{table}

\begin{longtable}{lll}
 \caption{A long Table}\\
    \toprule
    \csvreader[
        head=false,
        late after line=\\,
        filter equal={\thecsvinputline}{1},
        ]{longfile.csv}{}{\csvcoli & \csvcolii & \csvcoliii}
    \midrule
    \endfirsthead
    \toprule
        \csvreader[
        head=false,
        late after line=\\,
        filter equal={\thecsvinputline}{1},
        ]{longfile.csv}{}{\csvcoli & \csvcolii & \csvcoliii}
    \midrule
    \endhead
    \midrule
    \endfoot
    \bottomrule
    \endlastfoot
    \csvreader[
        head=false,
        late after line=\\,
        filter not equal={\thecsvinputline}{1},
        ]{longfile.csv}{}{\csvcoli & \csvcolii & \csvcoliii}
\end{longtable}
\end{document}