Hello All: I am starting to work on a file comparison script where I have to compare the contents of two large files. Originally I thought to just sort on a numeric key, and use UNIX's comm to do a line by line comparison. However, this would fail, hence my thinking that I really should've just used Python from the start. Let me outline the problem.
Imagine two text files, f1 and f2, f1 is 1 2 3 4 5 and f2 is 12 2 3 4 5 where each line can be thought of as a record, not a running sentence. Okay, this one is easy, in fact, this is just a line by line comparison using comm -3 f1 f2. BUT... (and this is why I'm thinking of using Python's difflib to work on it) Now say f1 is 1 2 3 4 5 and f2 is 2 3 4 5 The only difference of the *contents* is 1, but if you did a line by line comparison, all of them would return because of the line difference at the beginning. So, what I'm really looking for, is not just a line by line comparison, but a file contents comparison. Ideally, all I want to generate is a file of lines which would contain the differences. My first thought is to do a sweep, where the first sweep takes one line from f1, travels f2, if found, deletes it from a tmp version of f2, and then on to the second line, and so on. If not found, it writes to a file. At the end, if there are also lines still in f1 that never were matched because it was longer, it appends those as well to the difference file. At the end, you have a nice summary of the lines (i.e., records) which are not found in either file. Any suggestions where to start? -- http://mail.python.org/mailman/listinfo/python-list
