On Apr 14, 5:03 pm, Paul Rubin <http://[EMAIL PROTECTED]> wrote: > In the course of writing a bunch of generator-oriented code I kept > wanting to temporarily truncate the output of generators for debugging, > i.e. I might have a function like > > def generate_bazillion_items(): > for line in bazillion_line_file: > yield itemify(line) > > where I wanted to test the program on just the first 20 lines of the > file. After a number of rounds of editing the program to wrap an > xrange(20) loop I went to using islice(bazillion_line_file, 20), but > even more handy was to write this decorator: > > def truncate(n): > from itertools import islice > def trunc(gen): # truncate generator to n items > return lambda *a,**kw: islice(gen(*a,**kw), n) > return trunc > > Then to chop bazillion_items to 20 items, I just write: > > @truncate(20) > def generate_bazillion_items(): > for line in bazillion_line_file: > yield itemify(line) > > When I want to run the whole file, I comment out the @truncate line, > and if I want to debug again, I just uncomment it.
You should add this to the Python Wiki at http://wiki.python.org/moin/PythonDecoratorLibrary -- Paul -- http://mail.python.org/mailman/listinfo/python-list
