On Dec 1, 3:15 am, Tim Harig <user...@ilthio.net> wrote: > On 2010-12-01, javivd <javiervan...@gmail.com> wrote: > > > > > On Nov 30, 11:43 pm, Tim Harig <user...@ilthio.net> wrote: > >> On 2010-11-30, javivd <javiervan...@gmail.com> wrote: > > >> > I have a case now in wich another file has been provided (besides the > >> > database) that tells me in wich column of the file is every variable, > >> > because there isn't any blank or tab character that separates the > >> > variables, they are stick together. This second file specify the > >> > variable name and his position: > > >> > VARIABLE NAME POSITION (COLUMN) IN FILE > >> > var_name_1 123-123 > >> > var_name_2 124-125 > >> > var_name_3 126-126 > >> > .. > >> > .. > >> > var_name_N 512-513 (last positions) > > >> I am unclear on the format of these positions. They do not look like > >> what I would expect from absolute references in the data. For instance, > >> 123-123 may only contain one byte??? which could change for different > >> encodings and how you mark line endings. Frankly, the use of the > >> world columns in the header suggests that the data *is* separated by > >> line endings rather then absolute position and the position refers to > >> the line number. In which case, you can use splitlines() to break up > >> the data and then address the proper line by index. Nevertheless, > >> you can use file.seek() to move to an absolute offset in the file, > >> if that really is what you are looking for. > > > I work in a survey research firm. the data im talking about has a lot > > of 0-1 variables, meaning yes or no of a lot of questions. so only one > > position of a character is needed (not byte), explaining the 123-123 > > kind of positions of a lot of variables. > > Then file.seek() is what you are looking for; but, you need to be aware of > line endings and encodings as indicated. Make sure that you open the file > using whatever encoding was used when it was generated or you could have > problems with multibyte characters affecting the offsets.
Ok, I will try it and let you know. Thanks all!! -- http://mail.python.org/mailman/listinfo/python-list