for循環功能

Question

我的python知識仍然有限，我不知道如何在django中執行這個函數和類。 後來，而不是打印我會做四個查詢循環到原始數據庫，有人可以幫助我做到這一點正確的方式嗎？

class WeeklyReports(models.Model): 
    def FourWeeks(self, year, week): 
     self.year = year 
     self.week = week 
     end = datetime(year, 1, 1) + relativedelta(weeks=week-1, weekday=SU) 
     start = end - relativedelta(weeks=4, weekday=MO) 
     mint, maxt = datetime.min.time(), datetime.max.time() 
     for dt in rrule(WEEKLY, start, count=4): 
      yield dt.combine(dt, mint), dt.combine(dt + timedelta(days=6), maxt) 
      for start, end in FourWeeks(year, week): 
       print start, end    

我有望獲得類似的東西就如這裏countdown 4 weeks (week by week) back with python/django

但我得到這個：

>>> from weeklyreport.models import WeeklyReports 
>>> w = WeeklyReports() 
>>> w.FourWeeks(2013, 22) 
<generator object FourWeeks at 0x1eb5050> 
>>> w.FourWeeks(2013, 22) 
<generator object FourWeeks at 0x1eb50a0> 
>>> w.FourWeeks(2013, 22) 
<generator object FourWeeks at 0x1eb5050> 
>>> w.FourWeeks(2013, 22) 
<generator object FourWeeks at 0x1eb50a0> 

此查詢我將與打印後替換：

cursor = connections['nocdb'].cursor() 
cursor.execute("SELECT DISTINCT (p.name) AS platform, count(e.id) AS count FROM event e, lu_platform p WHERE e.platform_id = p.id AND e.sourcetype_id = 1 AND e.event_datetime BETWEEN %s AND %s AND e.sender_id NOT IN (759, 73) GROUP BY p.name ORDER BY p.name", [start, end]) 

Answer 1

你意圖在Python中寫作縮進問題：

class WeeklyReports(models.Model): 
    def FourWeeks(self, year, week): 
     self.year = year 
     self.week = week 
     end = datetime(year, 1, 1) + relativedelta(weeks=week-1, weekday=SU) 
     start = end - relativedelta(weeks=4, weekday=MO) 
     mint, maxt = datetime.min.time(), datetime.max.time() 
     for dt in rrule(WEEKLY, start, count=4): 
      yield dt.combine(dt, mint), dt.combine(dt + timedelta(days=6), maxt) 

然後，您可以通過執行打印：

w = WeeklyReports() 
for start, end in w.FourWeeks(year, week): 
    print start, end 

現在會發生什麼事是，w.FourWeeks(2013, 22)創建一個發電機（因爲你正在使用的yield語句），你只將「看」的結果時，你正在使用發生器。因此，只有在運行for start, end in FourWeeks(year, week):時纔會看到最後一部分的結果。