Creating string array from csv file

Question

I would like to create some name badges using a loop. I have a spreadsheet with names and affiliations that I save in names.csv file as follows

"Name1","Surname1","Affiliation1",
"Name2","Surname2","Affiliation2",
"Name3","Surname3","Affiliation3"

I can copy the content of names.csv in a string array and use a loop to recover the entries. The following is an example of working code producing the output Surname2:

\documentclass{article}
\usepackage{tikz}
\usepackage{pgf}
\usepackage{array}

\def\names{{"Name1","Surname1","Affiliation1",
"Name2","Surname2","Affiliation2",
"Name3","Surname3","Affiliation3"}}

\begin{document}

\pgfmathparse{\names[4]}\pgfmathresult

\end{document}

I can use this idea to create hundreds of name badges in a loop. But instead of writing the whole list in the .tex file I would like to call directly my names.csv file. I used the modified code

\documentclass{article}
\usepackage{tikz}
\usepackage{pgf}
\usepackage{array}

\def\names{{\input{names.csv}}}

\begin{document}

\pgfmathparse{\names[4]}\pgfmathresult

\end{document}

which apparently enters in an endless loop. I understood that \input{} works just as copy-pastying, but it doesn't seem the case. Of course I can work in the spreadsheet and then copy paste the names.csv file content, but I would like to understand what happens. Any clues?

PS edit: The suggested solution is enough for my case. But still I would like to be able to define macros with \input'. It seems that\input{}' inside a macro is not expanded immediately. I mean if I have some code in file.tex', that I want to plugin in a new macro,\def\mymacro{\input{file}}' will save \mymacro' as '\input{file}' and will only look what's inside the file when I call the macro in the document. That's why in the previous example\names' is not understood as an array. In the same way

\begin{filecontent*}{newfile.tex}
\input{file}
\end{filecontent*}

will save the code \input{file}' innewfile.tex', but not the content in `file.tex'. Anyone has any idea how to force input to expand?

Answer 1

Instead of importing the whole csv file you can read it row wise. There are some packages for this, here I use csvsimple. The file names.csv is created by the filecontents environment just to have it all in one file for this example.

\documentclass{article}
\usepackage{filecontents}
%% Create file
\begin{filecontents*}{names.csv}
Name1, Surname1, Affiliation1
Name2, S. Urname2, A f filiation2
Name3, Surname3, Affiliation3
Name4, Surname4, Affiliation4
Name5, Surname5, Affiliation5
\end{filecontents*}
\usepackage{tikz}
\usepackage{csvsimple}
\begin{document}
List of participants:
\begin{itemize}
  \csvreader[no head]{names.csv}{1=\name, 2=\surname, 3=\affiliation}{%
  \item \name\ \surname\ at \affiliation
  }
\end{itemize}

Badges:\newline
\csvreader[no head]{names.csv}{1=\name, 2=\surname, 3=\affiliation}{%
  \begin{tikzpicture}
    \draw[clip] (0,0) rectangle (6,4);
    \node at (3,2){\Large\name\ \surname};
    \node at (3,1.3){\affiliation};
    %% Logo
    \fill[color=red!40] (0.7,3.3) circle(1);
    \node[fill=green!40,opacity=0.5,rounded corners=5pt,anchor=west] at (0.8,3.5){\textsf{The Epic Event}};
    \node[anchor=west] at (0.8,3.5){\textsf{The Epic Event}};
  \end{tikzpicture}
}

\end{document}

Answer 2

The readarray package is set up to digest file data into arrays.

\documentclass{article}
\usepackage{filecontents}
\begin{filecontents*}{names.csv}
Name1,Surname1,Affiliation1,
Name2,Surname2,Affiliation2,
Name3,Surname3,Affiliation3
\end{filecontents*}
\usepackage{tikz}
\usepackage{pgf}
\usepackage{array}

\usepackage{readarray}
\readarraysepchar{,}
\begin{document}

\readdef{names.csv}\namedata

\readarray\namedata\names[-,\ncols]

\names[2,2] and \names[3,3]
\end{document}

Answer 3

You need to define \names so that its definition is the contents of the file. This means some expansion is required:

\documentclass{article}
\usepackage{tikz}
\usepackage{pgf}
\usepackage{array}

\begingroup
\makeatletter
\endlinechar=-1\relax
\everyeof{\noexpand}\relax
\edef\x{\endgroup\def\noexpand\names{{\@@input names.csv }}}\x

\begin{document}

\pgfmathparse{\names[4]}\pgfmathresult

\end{document}