django-timeseries 1.0.2

要求

支持 Django 版本 1.8+，适用于在 PostgreSQL 上运行的项目。

安装

pip install django-timeseries

用法

from datetime import timedelta
from django.db import models
from timeseries.utils import TimeSeriesModel, TimeSeriesManager


class Ad(models.Model):

    objects = TimeSeriesManager()


class RawAdData(TimeSeriesModel):

    TIMESERIES_INTERVAL = timedelta(days=1)  # update daily N.B integers in seconds also work

    NOT_AVAILABLE = -1

    ad = models.ForeignKey(Ad, related_name='rawdata')

    views = models.BigIntegerField(default=NOT_AVAILABLE)
    clicks = models.BigIntegerField(default=NOT_AVAILABLE)


class MonthlyAdReport(TimeSeriesModel):

    TIMESERIES_INTERVAL = timedelta(days=28)

    ad = models.ForeignKey(Ad, related_name='monthlyreports')

    avg_view_growth = models.FloatField()
    avg_click_growth = models.FloatField()


def ad_data_collector(queryset):
    """
        should return an iterable that yields dictionaries of data
        needed to successfully create a RawAdData instance
    """
    return ...


def report_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()
>>> print ad.latest_rawaddata, ad.latest_monthlyreports

TimeSeries QuerySet 方法

timeseries.utils.TimeSeriesQuerySet

向 Django QuerySet API 添加了 4 个主要方法，可用于更新和维护时间序列数据。这些方法包括

• prefetch_latest

• filter_outdated

• last_updated

• update_timeseries

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

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

其他实用工具

LatestQ

timeseries.utils

输入: related_name, **kwargs

返回值：django.db.models.Q 实例

构建一个 django.db.models.Q 实例，允许查询针对最新关联的反向关系。

注意：此方法旨在与 timeseries.utils.TimeSeriesQuerySet.last_updated 一起使用。

用法

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