common.py

common.py

'common, fun python functions that I seem to rewrite everywhere'
import itertools, sys

# stolen from itertools recipes
def chunk(iterable, batch_size, fillvalue=None):
    'breaks up iterator into chunks of batch_size'
    args = [iter(iterable)] * batch_size
    return itertools.izip_longest(fillvalue=fillvalue, *args)



def safe_chunk(iterable, batch_size):
    'like chunk(...) but filters out leftover null values'
    return (itertools.ifilter(lambda x: x, members)
            for members in chunk(iterable, batch_size, fillvalue=None))



def info(msg):
    print >> sys.stderr, '[INFO] {}'.format(msg)



def warn(msg):
    print >> sys.stderr, '[WARN] {}'.format(msg)