def itermultirangeaggregate(source, key, width, aggregation, minv, maxv):
aggregation = OrderedDict(aggregation.items()) # take a copy
it = iter(source)
srcflds = it.next()
# push back header to ensure we iterate only once
it = itertools.chain([srcflds], it)
# normalise aggregators
for outfld in aggregation:
agg = aggregation[outfld]
if callable(agg):
aggregation[outfld] = None, agg
elif isinstance(agg, basestring):
aggregation[outfld] = agg, list # list is default
elif len(agg) == 1 and isinstance(agg[0], basestring):
aggregation[outfld] = agg[0], list # list is default
elif len(agg) == 1 and callable(agg[0]):
aggregation[outfld] = None, agg[0] # aggregate whole rows
elif len(agg) == 2:
pass # no need to normalise
else:
raise Exception('invalid aggregation: %r, %r' % (outfld, agg))
outflds = [key]
for outfld in aggregation:
outflds.append(outfld)
yield tuple(outflds)
for k, rows in rowgroupbybin(it, key, width, minv=minv, maxv=maxv):
outrow = [k]
for outfld in aggregation:
srcfld, aggfun = aggregation[outfld]
if srcfld is None:
aggval = aggfun(rows)
outrow.append(aggval)
else:
idx = srcflds.index(srcfld)
# try using generator comprehension
vals = (row[idx] for row in rows)
aggval = aggfun(vals)
outrow.append(aggval)
yield tuple(outrow)
def itersimplerangeaggregate(table, key, width, aggregation, value, minv, maxv):
if aggregation == len:
aggregation = lambda grp: sum(1 for _ in grp) # count length of iterable
yield (key, 'value')
for k, grp in rowgroupbybin(table, key, width, value=value, minv=minv, maxv=maxv):
yield k, aggregation(grp)
def iterrangerowreduce(table, key, width, reducer, fields, minv, maxv):
yield tuple(fields)
for k, grp in rowgroupbybin(table, key, width, minv=minv, maxv=maxv):
yield tuple(reducer(k, grp))
