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Groups > comp.lang.python > #65495

Re: parse a csv file into a text file

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On 2014-02-05 16:10, Zhen Zhang wrote:
> import csv
> file = open('raw.csv')

Asaf recommended using string methods to split the file.  Keep doing
what you're doing (using the csv module), as it attends to a lot of
edge-cases that will trip you up otherwise.  I learned this the hard
way several years into my Python career. :-)

> reader = csv.reader(file)
> 
> f = open('NicelyDone.text','w')
> 
> for line in reader:
>       f.write("%s %s"%line[1],%line[5])

Here, I'd start by naming the pieces that you get, so do

  for line in reader:
    location = line[1]
    value = line[5]

> Also, I have to process the first column eg, "Toronto (Ont.)" into
> "Toronto". I am familiar with the function find(), I assume that i
> could extract Toronto out of Toronto(Ont.) using "(" as the
> stopping character, but based on my research , I have no idea how
> to use it and ask it to return me the string(Toronto).

You can use the .split() method to split a string, so you could do
something like

  if '(' in location:
    bits = location.split('(')
    # at this point, bits = ['Toronto ', 'Ont.)']
    location = bits[0].strip() # also strip it to remove whitespace

> 1:What is the data format for line[1], if it is string how come
> f.write()does not work. if it is not string, how do i convert it to
> a string?

The problem is not that "it is not a string" but that you passing
multiple parameters, the second of which is invalid Python because it
has an extra percent-sign.  First create the one string that you
want to output:

  output = "%s %s\n" % (location, bits)

and then write it out to the file:

  f.write(output)

rather than trying to do it all in one pass.

-tkc

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Thread

parse a csv file into a text file Zhen Zhang <zhen.zhang.uoft@gmail.com> - 2014-02-05 16:10 -0800
  Re: parse a csv file into a text file Asaf Las <roegltd@gmail.com> - 2014-02-05 16:17 -0800
    Re: parse a csv file into a text file Zhen Zhang <zhen.zhang.uoft@gmail.com> - 2014-02-05 23:56 -0800
  Re: parse a csv file into a text file Roy Smith <roy@panix.com> - 2014-02-05 19:33 -0500
    Re: parse a csv file into a text file Zhen Zhang <zhen.zhang.uoft@gmail.com> - 2014-02-05 23:52 -0800
      Re: parse a csv file into a text file Asaf Las <roegltd@gmail.com> - 2014-02-06 00:15 -0800
        Re: parse a csv file into a text file Asaf Las <roegltd@gmail.com> - 2014-02-06 00:48 -0800
      Re: parse a csv file into a text file MRAB <python@mrabarnett.plus.com> - 2014-02-06 13:16 +0000
        Re: parse a csv file into a text file Rustom Mody <rustompmody@gmail.com> - 2014-02-06 05:20 -0800
  Re: parse a csv file into a text file MRAB <python@mrabarnett.plus.com> - 2014-02-06 00:34 +0000
    Re: parse a csv file into a text file Zhen Zhang <zhen.zhang.uoft@gmail.com> - 2014-02-06 00:01 -0800
  Re: parse a csv file into a text file Tim Chase <python.list@tim.thechases.com> - 2014-02-05 18:46 -0600
    Re: parse a csv file into a text file Asaf Las <roegltd@gmail.com> - 2014-02-05 19:59 -0800
      Re: parse a csv file into a text file Tim Chase <python.list@tim.thechases.com> - 2014-02-05 22:09 -0600
        Re: parse a csv file into a text file Asaf Las <roegltd@gmail.com> - 2014-02-05 20:17 -0800
    Re: parse a csv file into a text file Zhen Zhang <zhen.zhang.uoft@gmail.com> - 2014-02-06 00:07 -0800
      Re: parse a csv file into a text file Tim Chase <python.list@tim.thechases.com> - 2014-02-06 12:49 -0600
  Re: parse a csv file into a text file Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-06 00:50 +0000
  Re:parse a csv file into a text file Dave Angel <davea@davea.name> - 2014-02-05 19:57 -0500
    Re: parse a csv file into a text file Zhen Zhang <zhen.zhang.uoft@gmail.com> - 2014-02-06 00:12 -0800
      Re: parse a csv file into a text file Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2014-02-06 10:49 +0200
      Re: parse a csv file into a text file Dave Angel <davea@davea.name> - 2014-02-06 06:35 -0500
      Re: parse a csv file into a text file Dave Angel <davea@davea.name> - 2014-02-06 06:53 -0500
  Re: parse a csv file into a text file Terry Reedy <tjreedy@udel.edu> - 2014-02-05 22:01 -0500
  Re: parse a csv file into a text file Neil Cerutti <neilc@norwich.edu> - 2014-02-06 14:02 +0000
  Re: parse a csv file into a text file Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-06 17:40 +0000
  Re: parse a csv file into a text file Tim Chase <python.list@tim.thechases.com> - 2014-02-06 11:51 -0600
  Re: parse a csv file into a text file Tim Golden <mail@timgolden.me.uk> - 2014-02-06 18:05 +0000
  Re: parse a csv file into a text file Neil Cerutti <neilc@norwich.edu> - 2014-02-06 18:34 +0000
  Re: parse a csv file into a text file Tim Chase <python.list@tim.thechases.com> - 2014-02-06 12:51 -0600

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