Adds an Iter class

The Iter class serves as a convenience rwrapper around the `async_iter` function

django_q/tasks.py

@@ -427,6 +427,67 @@ def async_chain(chain, group=None, cached=Conf.CACHED, sync=Conf.SYNC, broker=No
     return group
 
 
+class Iter(object):
+    """
+    An async task with iterable arguments
+    """
+
+    def __init__(self, func=None, args=None, kwargs=None, cached=Conf.CACHED, sync=Conf.SYNC, broker=None):
+        self.func = func
+        self.args = args or []
+        self.kwargs = kwargs or {}
+        self.id = ''
+        self.broker = broker or get_broker()
+        self.cached = cached
+        self.sync = sync
+        self.started = False
+
+    def append(self, *args):
+        """
+        add arguments to the set
+        """
+        self.args.append(args)
+        if self.started:
+            self.started = False
+
+    def run(self):
+        """
+        Start queueing the tasks to the worker cluster
+        :return: the task id
+        """
+        self.kwargs['cached'] = self.cached
+        self.kwargs['sync'] = self.sync
+        self.kwargs['broker'] = self.broker
+        self.id = async_iter(self.func, self.args, **self.kwargs)
+        self.started = True
+        return self.id
+
+    def result(self, wait=0):
+        """
+        return the full list of results.
+        :param int wait: how many milliseconds to wait for a result
+        :return: an unsorted list of results
+        """
+        if self.started:
+            return result(self.id, wait=wait, cached=self.cached)
+
+    def fetch(self,  wait=0):
+        """
+        get the task result objects.
+        :param int wait: how many milliseconds to wait for a result
+        :return: an unsorted list of task objects
+        """
+        if self.started:
+            return fetch(self.id, wait=wait, cached=self.cached)
+
+    def length(self):
+        """
+        get the length of the arguments list
+        :return int: length of the argument list
+        """
+        return len(self.args)
+
+
 class Chain(object):
     """
     A sequential chain of tasks

django_q/tests/test_cached.py

@@ -5,7 +5,7 @@ import pytest
 from django_q.cluster import pusher, worker, monitor
 from django_q.conf import Conf
 from django_q.tasks import async, result, fetch, count_group, result_group, fetch_group, delete_group, delete_cached, \
-    async_iter, Chain, async_chain
+    async_iter, Chain, async_chain, Iter
 from django_q.brokers import get_broker
 
 
@@ -100,7 +100,21 @@ def test_iter(broker):
     assert result(t2) is not None
     assert result(t3) is not None
     assert result(t4)[0] == 1
-    # test cached iter result
+    # test iter class
+    i = Iter('math.copysign', sync=True, cached=True)
+    i.append(1, -1)
+    i.append(2, -1)
+    i.append(3, -4)
+    i.append(5, 6)
+    assert i.started is False
+    assert i.length() == 4
+    assert i.run() is not None
+    assert len(i.result()) == 4
+    assert len(i.fetch().result) == 4
+    i.append(1, -7)
+    assert i.result() is None
+    i.run()
+    assert len(i.result()) == 5
 
 
 @pytest.mark.django_db