如何转换存储为两列(开始、结束)的日期范围以创建新的行索引并为值创建累积率?

How to transform date range stored as two columns (start, end) to create new row index and create accumulated rate for values?

我想知道如何转换存储为两列(开始、结束)的日期范围以创建新的行索引?例如我想转换以下数据:

    end         start     value
0   2000-01-04  2000-01-02  6
1   2000-01-05  2000-01-03  9

收件人:

date      rate
2000-01-02  2
2000-01-03  5
2000-01-04  5
2000-01-05  3

注:

start 和 end 显示了一个范围,rate 是在时间范围内分布的值,我正在寻找每天所有汇率的总和

import pandas as pd
import numpy as np
import io

temp=u"""end,start,value
2000-01-04,2000-01-02,6
2000-01-05,2000-01-03,9"""

df = pd.read_csv(io.StringIO(temp), parse_dates = [0,1])
print df
#change ordering for filling date from start to end
df = df[['start', 'end', 'value']]

#value divided difference of start and end, but it cant count first day, so has to be added
df['value'] = df['value']/(df['end'] + pd.Timedelta('1 days')- df['start']).astype('timedelta64[D]')

df['Id'] = df.index
#reshape datetimes from rows to columns
df = pd.melt(df, id_vars=[ 'value','Id'], var_name=['D'], value_name='Date')
#remove unnecessary column D
del df['D']
print df
#   value  Id       Date
#0      2   0 2000-01-02
#1      3   1 2000-01-03
#2      2   0 2000-01-04
#3      3   1 2000-01-05

#set multiindex
df = df.set_index(['Id', 'Date' ])

#fill gap between start and end dates
f = lambda df: df.asfreq("D", method='ffill')
df = df.reset_index(level=0).groupby('Id').apply(f)

del df['Id']
df = df.reset_index()
print df
#   Id       Date  value
#0   0 2000-01-02      2
#1   0 2000-01-03      2
#2   0 2000-01-04      2
#3   1 2000-01-03      3
#4   1 2000-01-04      3
#5   1 2000-01-05      3

#sum column value to column rate
df['rate'] = df.groupby('Date')['value'].transform('sum')
#delete unnecessary columns
df = df.drop(['Id', 'value'], axis=1 )
#drop duplicity
df = df.drop_duplicates()
print df
#
#        Date  rate
#0 2000-01-02     2
#1 2000-01-03     5
#2 2000-01-04     5
#5 2000-01-05     3