problem ith reading & writing text-files

[szallah]

hi...
i'm having difficulties handling textfiles...
there's a function to read each line of a textfile, and then append all lines to another textfile...

that's the code:

file_var = open(base_dir+filename)
data = file_var.readlines()
file_var.close()
db = file(other_dir+second_filename,'a')
db.writelines(data)
db.close()

basically everything's working fine... the second file looks (in my windows notepad) exactly as the file from where the data is copied from.

but:
there's another function in the code, which takes values from the textfile and calculates something. and even though the content looks exactly the same, the function doesn't calculate the values from the second file.
if i replace the second file with the original file, everything is working fine.

any ideas why the second file doesn't work?

btw:
if i execute the same script on my pc, the second file is working. so i really don't know why it's not working on my cell-phone...

[shubhendra]

Hi szallah,
it would have been better if you could show the code which wasn't working.

P.S.:- While appending in a file, if file is already existing then copied things appear on second line of file. Else if file does exist then copied things appear on first line of this file.

I never noticed that before.

[szallah]

EDIT:
problem is solved now. i just mixed up two values. collumn 1 was written in collumn 2 and vice versa. no wonder the calculation didn't work...

original post:
before data is appended, the target always get's cleared. therefore, appending always starts in line 1.
i got it working now, by writing the file in binary mode. so simply copying the file is now working.

unfortunately, i want to create another file, which contains only some of the data of the already copied file. getting all the data in the thrid file is working fine. but again, the programm can't read from that file. and in this case, writing in binary-mode is not working.

basically what want to do is (from the beginning):
1. copy the content of multiple text-files on drive e to one file on drive c... working now with binary mode...
2. copy lines matching a defined criteria from created file on drive c to another file.
3. use data from created file for further calculations

basically the filecontent looks like this:
123,123,text1
456,456,text2
789,789,text3

i've built some functions, which combined together:
- build a list where every element contains a string of the corresponding line of the textfile
- split the strings at the ',' to build another list which would look like this:

print list[0][0]+' '+list[0][1]+' '+list[0][2]
-> 123 123 text1

- the content of the list is then used for calculations etc., and the list-elements with certain results are merged together in another list, looking like the first one.
- the content of this last list gets written in the new text-file.
- the content of the new file should be used again for calculations. but this time it's nor working.

unfortunately the code is a real mess right now, so i can't really just post a few functions...
i guess i'll have to figure it out myself...