Ah, but what if the data itself has tabs! Doh!
It can be a mess either way. There are standards (or conventions?) for
escaping internal commas in CSV -- which doesn't mean the software that
was used to produce the CSV, or the software you are using to read it,
actually respects them.
But I'm not sure if there are even standards/conventions for escaping
tabs in a tab-delimited text file?
Really, the lesson to me is that you should always consider use an
existing well-tested library for both reading and writing these files,
whether CSV or tab-delimited -- even if you think "Oh, it's so simple,
why bother than that." There will be edge cases. That you will discover
only when they cause bugs, possibly after somewhat painful debugging. A
well-used third-party library is less likely to have such edge case bugs.
I am more ruby than python; in ruby there is a library for reading and
writing CSV in the stdlib.
http://ruby-doc.org/stdlib-1.9.3/libdoc/csv/rdoc/CSV.html
On 11/25/13 12:57 PM, Roy Tennant wrote:
Also, just to be clear, the data file is a tab-delimited text file, not a
CSV (comma-separated quoted values) file. Whenever processing data it's
important to be clear about what format you are working with. I happen to
prefer tab-delimited text files over CSV myself, as in this case like in
many others, the data itself can have quotes, which can play havoc on a
program expecting them only as delimiters.
Roy
On Mon, Nov 25, 2013 at 9:49 AM, Joshua Gomez <[email protected]> wrote:
If all you want to do is add a tab to the beginning of each line, then you
don't need to bother using the csv library. Just open your file, read it
line by line, prepend a tab to each line and write it out again.
src = open('noid_refworks.txt','rU')
tgt = open('withid.txt', 'w')
for line in src.readlines():
line = '\t%s' % line
tgt.write(line)
-Joshua
________________________________________
From: Code for Libraries <[email protected]> on behalf of Bohyun
Kim <[email protected]>
Sent: Monday, November 25, 2013 9:10 AM
To: [email protected]
Subject: [CODE4LIB] Tab delimited file with Python CSV
Hi all,
I am new to Python and was wondering if I can get some help with my short
script. What I would like the script to do is:
(1) Read the tab delimited file generated by Refworks
(2) Output exactly the same file but the blank column added in front.
(This is for prepping the exported tab delimited file from refworks so
that it can be imported into MySQL; so any suggestions in the line of
timtoady would be also appreciated.)
This is what I have so far. It works, but then in the output file, I end
up getting some weird character in each line in the second column (first
column in the original input file). I also don't really get what
escapechar=' ' does or what I am supposed to put in there.
import csv
with open('noid_refworks.txt','rU') as csvinput:
with open('withid.txt', 'w') as csvoutput:
dialect = csv.Sniffer().sniff(csvinput.read(1024))
csvinput.seek(0)
reader = csv.reader(csvinput, dialect)
writer = csv.writer(csvoutput, dialect, escapechar='\'',
quoting=csv.QUOTE_NONE)
for row in reader:
writer.writerow(['\t']+row)
A row in the original file is like this (Tab delimited and no quotations,
some fields have commas and quotation marks inside.):
Reference Type Authors, Primary Title Primary Periodical Full
Periodical Abbrev Pub Year Pub Date Free From Volume Issue
Start Page Other Pages Keywords Abstract Notes Personal
Notes Authors, Secondary Title Secondary Edition Publisher
Place Of Publication Authors, Tertiary Authors, Quaternary
Authors, Quinary Title, Tertiary ISSN/ISBN Availability
Author/Address Accession Number Language Classification Sub
file/Database Original Foreign Title Links DOI Call Number
Database Data Source Identifying Phrase Retrieved Date
Shortened Title User 1 User 2 User 3 User 4 User 5 User
6 User 7 User 8 User 9 User 10 User 11 User 12 User 13
User 14 User 15
A row in the output file is like this:
(The tab is successfully inserted. But I don't get why I have L inserted
after no matter what I put in escapechar)
LReference Type Authors, Primary Title Primary Periodical
Full Periodical Abbrev Pub Year Pub Date Free From Volume
Issue Start Page Other Pages Keywords Abstract Notes
Personal Notes Authors, Secondary Title Secondary Edition
Publisher Place Of Publication Authors, Tertiary Authors,
Quaternary Authors, Quinary Title, Tertiary ISSN/ISBN
Availability Author/Address Accession Number Language
Classification Sub file/Database Original Foreign Title Links
DOI Call Number Database Data Source Identifying Phrase
Retrieved Date Shortened Title User 1 User 2 User 3 User 4
User 5 User 6 User 7 User 8 User 9 User 10 User 11
User 12 User 13 User 14 User 15
Any help or pointers would be greatly appreciated!
~Bohyun
