On Sat, 7 Feb 2009 01:06:06 -0800 (PST) Rhamphoryncus <rha...@gmail.com> wrote:
> On Feb 6, 10:21 pm, rdmur...@bitdance.com wrote: > > Quoth Mensanator <mensana...@aol.com>: > > > def flatten(listOfLists): > > > return list(chain.from_iterable(listOfLists)) > > > > Python 2.6.1 (r261:67515, Jan 7 2009, 17:09:13) > > [GCC 4.3.2] on linux2 > > Type "help", "copyright", "credits" or "license" for more > > information. >>> from itertools import chain > > >>> list(chain.from_iterable([1, 2, [3, 4]])) > > Traceback (most recent call last): > > File "<stdin>", line 1, in <module> > > TypeError: 'int' object is not iterable > > >>> list(chain(*[1, 2, [3, 4]])) > > Traceback (most recent call last): > > File "<stdin>", line 1, in <module> > > TypeError: 'int' object is not iterable > > >>> list(chain.from_iterable(['abcd', 'efg', [3, 4]])) > > ['a', 'b', 'c', 'd', 'e', 'f', 'g', 3, 4] > > What usecase do you have for such inconsistently structured data? I have a similar use case in pyspread, which is a Python spreadsheet that employs numpy object arrays. Since the Python objects in the numpy arrays are derived from user input, they can be anything, including nested lists as well as strings, etc. Since I consider my work-around that treats strings as a special case a rather ugly hack, I would welcome a robust, generic approach to the OP's problem. Martin -- http://mail.python.org/mailman/listinfo/python-list
