mjhjmtu

I am new in LaTeX. In tabular, we generally use & for partition. I want to create a .sty for tabular environment. Replace & with comma delimiter, in this case comma should be work as & like in tabular command.

In .tex file, input is a,b,c and output should look like |a|b|c|

Proof of concept. Use at your own risk!

The basic approach is to change catcode of the character you want to use as “alignment tab”. Here's a mytabular environment which does that:

documentclassarticle

usepackagexparse

ExplSyntaxOn
NewDocumentEnvironment mytabular O, 
 
 char_set_catcode_other:N &
 char_set_catcode_alignment:n `#1
 begintabular
 
 
 endtabular
 
ExplSyntaxOff

begindocument
pagestyleempty

beginmytabularl
 a , b & c \
 c , d \
endmytabular

beginmytabular[@]l
 a @ b \
 c @ d, & e \
endmytabular

enddocument

The optional argument lets you choose which character is used as alignment tab. No verification whatsoever is done to see if the character you passed is valid. If you don't pass a character, a comma is used. The & behaves as a normal character.

However, as other already warned you, this is not the best idea. Packages that rely on & being an alignment tab will break.

As Bernard suggested, why don't use csvsimple?

If you have commas in your cells, just put the contents within curly brackets.

If you have & in your cells, just write &.

documentclassarticle
usepackagefilecontents
usepackagecsvsimple

begindocument

beginfilecontents*mydata.csv
a,b,c
endfilecontents*
csvreader[
 tabular=|c|c|c|,
 nohead
 ]mydata.csv% filename
csvcoli & csvcolii & csvcoliii

vspace3ex
and if you have commas or & in your cells:
vspace3ex

beginfilecontents*mydata.csv
a,b,c
c, d,e, f, g,h, i, j, k
l & m,n & o, p,q & r & s & t
endfilecontents*
csvreader[
 tabular=|c|c|c|,
 nohead
 ]mydata.csv% filename
csvcoli & csvcolii & csvcoliii

enddocument

You can use the spalign package (documentation here), which includes spaligntabular that acts exactly like tabular, except it uses both space and comma as the align character & and semicolon as the the end-of-row control
sequence \:

documentclass[12pt]report
usepackagespalign

begindocument

spaligntabularlcra b c; aa bb cc

spaligntabularca,b,c

enddocument

It produces this:

and

The spalign package also includes similar commands, such as spalignmat for a matrix and spalignarray for a generic array.

There are options to use different characters instead of or in addition to space, comma, and semicolon (see the documentation).

By the way, if you need to include a comma, space, or semicolon in your table, just enclose it in braces .