def aggregate_properties(objects, aggregators):
"""Combine the properties of a list of objects.
Constructs a lazy dictionary (see class lazy_dict in utils.js) of
properties.
Arguments:
objects -- a list of Node or Edge objects
aggregators -- dictionary, specifies how to combine the
properties. For each item in aggregators, a property with the same
key is created. The aggregator value should be either a function,
in which case the property value is created by calling that
function on the list of objects; or a pair (function, prop), in
which case the property value is created by calling the function
on a list containing each object's value for property prop.
"""
def apply_aggregator(aggr):
"""Run aggregator with objects as arguments"""
if isinstance(aggr, tuple):
fun = aggr[0]
prop = aggr[1]
lst = [x[prop] for x in objects]
else:
fun = aggr
lst = objects
return fun(lst)
return map_dict_lazy(apply_aggregator, aggregators)
def aggregate_properties(objects, aggregators):
"""Combine the properties of a list of objects.
Constructs a lazy dictionary (see class lazy_dict in utils.js) of
properties.
Arguments:
objects -- a list of Node or Edge objects
aggregators -- dictionary, specifies how to combine the
properties. For each item in aggregators, a property with the same
key is created. The aggregator value should be either a function,
in which case the property value is created by calling that
function on the list of objects; or a pair (function, prop), in
which case the property value is created by calling the function
on a list containing each object's value for property prop.
"""
def apply_aggregator(aggr):
"""Run aggregator with objects as arguments"""
if isinstance(aggr, tuple):
fun = aggr[0]
prop = aggr[1]
lst = [x[prop] for x in objects]
else:
fun = aggr
lst = objects
return fun(lst)
return map_dict_lazy(apply_aggregator, aggregators)