Python Pandas 中如何按时间间隔对数据进行分组?
原文:https://www . geesforgeks . org/如何按时间间隔分组数据-python-pandas/
先决条件:T2】熊猫
当您遇到时间序列分析时,按时间间隔对数据进行分组是非常明显的。时间序列是按时间顺序索引(或列出或绘制)的一系列数据点。最常见的是,时间序列是在连续等间隔的时间点上取得的序列。
熊猫提供了两个非常有用的功能,我们可以用它们来对数据进行分组。
- 重采样()— 该功能主要用于时间序列数据。这是一种方便的时间序列频率转换和重采样方法。对象必须具有类似日期时间的索引(日期时间索引、周期索引或时间增量索引),或者将类似日期时间的值传递给 on 或 level 关键字。重采样根据实际数据生成唯一的采样分布。
语法: DataFrame.resample(规则,how=None,axis=0,fill_method=None,closed=None,label=None,约定='start ',kind=None,loffset=None,limit=None,base=0,on=None,level=None)
参数:
- Rule: An offset string or object representing the target conversion.
- axis: int, optional, default 0
- Closed: {[right] [left]}
Label: {[right], [left]}
loffset: Adjust the time stamp of resampling
- base: For the frequency of even subdivision for one day, the "origin" of the aggregation interval. For example, for the "5 minutes" frequency, the cardinality can be from 0 to 4. The default is 0.
- on: For a DataFrame, use columns instead of indexes to resample. Columns must be similar to datetime.
- Level: For a MultiIndex, the level (name or number) should be used for resampling. The level must be similar to datetime.
例:每月增加的数量,每年增加的总金额。
- grouper -grouper allows users to specify the basis on which users want to analyze data.
语法: dataframe.groupby(pd。Grouper(key,level,freq,axis,sort,label,convention,base,Ioffset,origin,offset))
参数:
- key: Select the target column to be grouped.
- level: the level of the target index.
- [t0 T0】 freq: group by specify the frequency. If the target column is an object with similar date and time,
- T30
- Convention: If grouper is PeriodIndex and freq parameter is passed,
- base: only works when freq is passed.
- ioffset: only works when freq is passed.
- Origin: Timestamp is based on
- Offset: The offset time increment is added to the origin 【T60】
方法
- 导入模块
- 加载或创建数据
- 根据需要对数据进行重新采样
- 将数据分组
下面给出了使用这种方法的实现:
使用中的数据帧: timeseries.csv
链接: 此处。
程序:使用重采样进行聚合
python 3
import numpy as np
import pandas as pd
# loading dataset
data = pd.read_csv('path of dataset')
# setting the index for the data
data = data.set_index(['created_at'])
# converting index to datetime index
data.index = pd.to_datetime(data.index)
# Changing start time for each hour, by default start time is at 0th minute
data.resample('W', loffset='30Min30s').price.sum().head(2)
data.resample('W', loffset='30Min30s').price.sum().head(2)
# we can also aggregate it will show quantity added in each week
# as well as the total amount added in each week
data.resample('W', loffset='30Min30s').agg(
{'price': 'sum', 'quantity': 'sum'}).head(5)
版权属于:月萌API www.moonapi.com,转载请注明出处