n00bie help with file input and parsing

[Greg Fortune]

Well, I just wrote a csv parser that will read that input file, but then 
realized that wasn't the main question in your post ;o)  Teach to me to 
stay up this late..


jason wrote:

> Hi All,
> 
> I am trying to write a program which takes the input from a csv file
> called input.txt.  This file contains the following:
> 
> "1","2","3","10064299","5","6","7","8","9"
> "1","2","3","10064862","5","6","7","8","9"
> "1","2","3","10064908","5","6","7","8","9"
> "1","2","3","10161170","5","6","7","8","9"
> "1","2","3","10161925","5","6","7","8","9"
> .....
> etc.
> 


#quick, dirty way
lines = string.split(inp, '\n')
for x in lines:
        print string.split(x, ',')[3]


> I also have files separate text files named QH10064299.txt,
> QH10064862.txt, QH10064908.txt etc.
> 
> Basically, what I need to do is parse the "10064299" string from the
> input.txt file, strip the quotation marks, and add a QH and .txt onto
> the end so it matches one of other separate files.  Then I need to
> open this file up in append mode, and add all the other information to
> it.

k, you should have the filename from above.  Just open the file in append 
mode..

> 
> For example, if I pulled the 10064299 from the 1st line of input, I
> would then add the QH and .txt to make QH10064299.txt.  Then I would
> open this file for appending and append:
> 
> 1
> 2
> 3
> 10064299
> 5
> 6
> 7
> 8
> 9
> 
> NB all quotes removed.  Someone told me this could be written in about
> 10 lines of Python code, could anyone help me out?  I have never
> before used Python.

cheating a little, you can do it in 5

lines = open('input.txt', 'r').readlines()
for x in lines:
        out = open('QH' + string.split(x, ',')[3], + '.txt', 'a')
        out.write(string.join(string.split(x, ','), '\n'))
        out.close()


Do yourself a favor and check out the excellent documentation available at 
python.org.  Download a copy for yourself..  As you get more familiar with 
the language, the Library Reference section is about the only thing you'll 
ever need :)


Greg Fortune
Fortune Solutions