[Tutor] Adding Value to CSV

[Dave Angel]

(Please don't top-post on a newsgroup that has the convention of adding 
new content after quoted text.)

Paras K. wrote:
> What I am trying to do is as I am writing the row to the CSV file, I want to
> add the string base on a few other checks that I still need to write.
>
> Ex.
>
> readline = '"152.88.91.98","BitTorrent Client Activity","1","2009-09-23
> 15:40:33"\r\n'
>
> At the end of this based on my checks I want to be able to write a string
> like
>
> Part of DHCP Pool or Part of VPN Pool
>
> So the final line should be something like this written to the CSV file:
>
> '"152.88.91.98","BitTorrent Client Activity","1","2009-09-23 15:40:33",
> "Part of DHCP Pool"
>
> Thanx in advance for the help.
>
> On Sun, Nov 1, 2009 at 7:16 AM, Dave Angel <davea at ieee.org> wrote:
>
>   
>> Paras K. wrote:
>>
>>     
>>> I have some code that is going through a number of test.
>>>
>>> When I have the line that has been read I need to add another value at the
>>> end of it, or write the information into another csv file
>>>
>>> Example of my code:
>>>
>>> for line in fh.readlines():
>>>            readline = line
>>>            ipline = readline
>>>            ip = ipline.split(' ')[0]
>>>            split_ip = ip.split('.')
>>>            if ((split_ip[0] == '"152')):
>>>                ff.write(readline)
>>>                totalcount +=1
>>>
>>>
>>> I need to add another piece, how can I add another field at the end of
>>> ff.write(readline)
>>>
>>>
>>> Any assistance would be greatly appreciated. Thank You.
>>>
>>>
>>>
>>>       
>> If your program is correct so far, then you could add it simply with:
>>            ff.write(readline + " " + newdata)
>>
>> Although your message subject says CSV, it looks like you're breaking the
>> line up by spaces.  So if in fact each field is constrained not to have a
>> space within, and there is a single space between fields, then the above
>> will work.
>>
>> If, on the other hand, you have to deal with fields that can contain the
>> delimiter, perhaps escaped or quoted, then things get much more complicated.
>>
>> DaveA
>>
>>     
>
>   

Now that your input format is entirely different than what your code can 
parse, my answer would have to be different as well.  If you were still 
doing it by hand, then you'd need to use strip() to remove the trailing 
newline, then concatenate with a comma, some quotes, and another newline.

But you probably ought to be using the csv module, since you're likely 
to come up with some fields having embedded commas in them, and split() 
cannot handle that.

Once you've got a csv.reader() and a csv.writer(), all you're looking 
for is  mydata.append(newdata)  to add newdata field to the end of a 
record.  The reader reads into a list, and the write writes from a list.

DaveA