django-timeseries 1.0.2

要求

在postgresql上运行的项目支持django版本1.8+。

安装

pip install django-timeseries

用法

fromdatetimeimporttimedeltafromdjango.dbimportmodelsfromtimeseries.utilsimportTimeSeriesModel,TimeSeriesManagerclassAd(models.Model):objects=TimeSeriesManager()classRawAdData(TimeSeriesModel):TIMESERIES_INTERVAL=timedelta(days=1)# update daily N.B integers in seconds also workNOT_AVAILABLE=-1ad=models.ForeignKey(Ad,related_name='rawdata')views=models.BigIntegerField(default=NOT_AVAILABLE)clicks=models.BigIntegerField(default=NOT_AVAILABLE)classMonthlyAdReport(TimeSeriesModel):TIMESERIES_INTERVAL=timedelta(days=28)ad=models.ForeignKey(Ad,related_name='monthlyreports')avg_view_growth=models.FloatField()avg_click_growth=models.FloatField()defad_data_collector(queryset):"""
        should return an iterable that yields dictionaries of data
        needed to successfully create a RawAdData instance
    """return...defreport_data_collector(queryset):"""
        should return an iterable that yields dictionaries of data
        needed to successfully create a MonthlyAdReport instance
    """return...# in a shell>>>Ad.objects.update_timeseries('rawdata',ad_data_collector)# this return the results of a bulk_create call from the RawAdData manager# for ads that hadn't been updated in the last day>>>Ad.objects.update_timeseries('monthlyreports',report_data_collector)# this return the results of a bulk_create call from the MonthlyAdReport# manager for ads that hadn't had a report generated in the last 28 days>>>ad=Ad.objects.prefetch_latest('rawdata','monthlyreports').first()>>>printad.latest_rawaddata,ad.latest_monthlyreports

TimeSeries QuerySet方法

timeseries.utils.TimeSeriesQuerySet

向django queryset api添加4个主要方法，这些方法可用于 更新和维护时间序列数据。这些方法包括：

• 预取最新
• 过滤器已过时
• 上次更新
• 更新时间序列

ad=Ad.objects.last_updated('rawdata').first()# assuming there's data related to adprintad.rawdata_last_updated# this will print the timestamp of when the associated data was# last updated

ad=Ad.objects.prefetch_latest('rawdata','monthlyreports').first()printad.latest_rawaddata,ad.latest_monthlyreports# this will print the reprs of the latest associated data# instances

其他实用程序

LatestQ

timeseries.utils

输入：related_name，**kwargs

返回：django.db.models.q instance

构造一个django.db.models.q实例，该实例允许查询 根据最新关联的反向关系执行。

注意：此方法设计用于与 timeseries.utils.timeseriesqueryset.last_已更新。

用法：

Ad.objects.last_updated('rawdata').filter(LatestQ('rawdata',views__gt=1000))