Save data as a *.dat file?
Correct me if I'm wrong, but opening, writing to, and subsequently closing a file should count as "saving" it. You can test this yourself by running your import script and comparing the last modified dates.
I am writing a program in Python which should import *.dat files, subtract a specific value from certain columns and subsequently save the file in *.dat format in a different directory. 
My current tactic is to load the datafiles in a numpy array, perform the calculation and then save it. I am stuck with the saving part. I do not know how to save a file in python in the *.dat format. Can anyone help me? Or is there an alternative way without needing to import the *.dat file as a numpy array? Many thanks!