In a message of Wed, 13 May 2015 22:27:11 -0700, Alex Kleider writes: >As a follow up question: >The following seems to work- > > for f_name in list_of_file_names: > for line in open(f_name, 'r'): > process(line) > >but should I be worried that the file doesn't get explicitly closed? > >Alex
If you use the with statement you will guarantee that the file closes as soon as you are done with it. It will also handle exceptions nicely for you. See: https://www.python.org/dev/peps/pep-0343/ In practice, Cpython's ref counting semantics means that running out of file descriptors doesn't happen (unless you put that code in a loop that gets called a whole lot). But the gc used by a Python version is not part of the language specification, but is a language implementation detail. If you are writing for PyPy or Jython you will need to use the with statement or close your files explicitly, so the gc knows you are done with them. Relying on 'the last reference to them went away' to close your file won't work if the gc isn't counting references. See: http://pypy.org/compat.html or for more detail: http://pypy.readthedocs.org/en/latest/cpython_differences.html#differences-related-to-garbage-collection-strategies Laura _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
