Print

Print


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 <[log in to unmask]> 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 <[log in to unmask]> on behalf of Bohyun
>> Kim <[log in to unmask]>
>> Sent: Monday, November 25, 2013 9:10 AM
>> To: [log in to unmask]
>> 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
>>
>
>