[Tutor] Comparing lines in two files, writing result into a t hird file

Scott Widney SWidney@ci.las-vegas.nv.us
Wed Apr 23 11:20:03 2003


> I have two files, file1.txt and file 2. txt, each containing 
> numbers.  I want to compare the numbers in the files and put
> an asterisk at the end of the numbers that match, writing the
> result into a third file

> I've tried various combinations of opening the files and 'if' 
> nests, but I can't seem to get it right.  Any hints on what
> structure to use.  Thanks in advance.

Hints? Dictionary! Use a dictionary to record the numbers in the first file.
Then compare the numbers in the second file, giving a meaningful value to
those that are duplicated and just recording the others. You now have enough
information to write your third file.


> I have two files, file1 and file2.  I want to print the first 
> line from file1, then the first line from file2, then the second
> line from file 1, then the second line from file 2, etc.

Not sure if this was yours also, but as another hint: check your version of
python. If it's 2.0 or greater, check the Library Reference for the built-in
function zip().


Scott