Here is a shell command (MS-DOS): debug\curve-fit <input.txt >output.txt
And here is a Python script that *should* do the same thing (and almost does): import os inputfilename = 'input.txt' outputfilename = 'output.txt' inputfile = open(inputfilename,'r') outputfile = open(outputfilename,'w') inputstream,outputstream = os.popen2("debug\\curve-fit") inputstream.write(inputfile.read()) inputfile.close() inputstream.close() outputfile.write(outputstream.read()) outputstream.close() outputfile.close() In the shell command, my curve-fit program processes the entire input file. In the Python script, my curve-fit program processes all except for the last line. Adding an extra newline to the end of my input file fixes this problem. What did I do wrong that led to this small difference? On a side note, I am very new to Python so I would appreciate any comments on style, or suggestions for simpler ways to write something like this (seems overkill for matching one line of shell), or more portable ways to write it (requires '\\' on windows but '/' on linux). -- http://mail.python.org/mailman/listinfo/python-list