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Re: Writing and reading a comma delimited or tab delimited file one record at a time

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  • Subject: [mg69116] Re: [mg68255] Writing and reading a comma delimited or tab delimited file one record at a time
  • From: Igor Antonio <igora at>
  • Date: Wed, 30 Aug 2006 06:34:03 -0400 (EDT)
  • References: <>
  • Reply-to: igora at
  • Sender: owner-wri-mathgroup at

Richard Palmer wrote:
> I need to be able to write a large file with delimited fields with a
> new line symbol separating records.  Since the files can be very
> large, I can't create or read them all at once and work with them in
> memory.  It would be nice to create small sample files I can look at
> in EXCEL (I'm on a MAC).  The files I need to create consist of 5
> string valued fields and a positive real number.  I suspect this is
> simple, but I can not see a simple way to do it from the
> documentation:  The goal is to take
> alfa code 1
> ...
> alfa code 5
> amount
> to
> alfa code1, alfa code 2, ... , alfa code t, amount \nl
> (the comma is a ',' or  some other separator) in writing the file and,
> correspondingly, be able to read the file back
> I guess I'm a little surprised there are no ImportLine or ExportLine
> commands corresponding to the Import and Export commands.  It's always
> nice to be able to work with all the data.  However, sometimes there
> is too much data and we need to be able to work with summaries.
> Thanks

Mathematica has "lower-level" functions that let you read/write to a 
file.  Take a look at the documentation:

Built-In functions > Input and Output > File Output.

Take a look at Write and WriteString, specifically.


Igor C. Antonio
Wolfram Research, Inc.

To email me personally, remove the dash.

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