rrule.py 文件源码

def _iter(self):
        rlist = []
        self._rdate.sort()
        self._genitem(rlist, iter(self._rdate))
        for gen in [iter(x) for x in self._rrule]:
            self._genitem(rlist, gen)
        exlist = []
        self._exdate.sort()
        self._genitem(exlist, iter(self._exdate))
        for gen in [iter(x) for x in self._exrule]:
            self._genitem(exlist, gen)
        lastdt = None
        total = 0
        heapq.heapify(rlist)
        heapq.heapify(exlist)
        while rlist:
            ritem = rlist[0]
            if not lastdt or lastdt != ritem.dt:
                while exlist and exlist[0] < ritem:
                    exitem = exlist[0]
                    advance_iterator(exitem)
                    if exlist and exlist[0] is exitem:
                        heapq.heapreplace(exlist, exitem)
                if not exlist or ritem != exlist[0]:
                    total += 1
                    yield ritem.dt
                lastdt = ritem.dt
            advance_iterator(ritem)
            if rlist and rlist[0] is ritem:
                heapq.heapreplace(rlist, ritem)
        self._len = total