Question

我有一个像这样的熊猫日期框架：

       maturity              coupon     freq
0 2018-06-01 00:00:00         3         1
1 2017-10-01 00:00:00         2         1

我想要一个矩阵，在第一列中包含这些日期和日期1,2，......这些日期之前的年份，第二列包含从2016.03.04到日期的天数。

像这样：

    date                  number of days remaining
 2016-06-01 00:00:00          89
 2016-10-01 00:00:00          211    
 2017-06-01 00:00:00          454
 2017-10-01 00:00:00          576
 2018-06-01 00:00:00          819

请帮忙！

Answer 1

您可以尝试通过将DataFrame添加到列出Series然后DataOffset来附加新dfs来创建新的d。最后，您可以减去日期时间Timedelta，np.timedelta由integer转换为d = "2016.03.04" #append substracted column maturity with DateOffset dfs =[] for i in range(5): years_before = df['maturity'] - pd.DateOffset(years=i) #get only datetime to date d #print years_before.loc[years_before > d] dfs.append(years_before.loc[years_before > d]) df = pd.DataFrame(pd.concat(dfs, ignore_index=True)) print df maturity 0 2018-06-01 1 2017-10-01 2 2017-06-01 3 2016-10-01 4 2016-06-01：

df['remain'] = (df['maturity'] - pd.to_datetime(d)) / np.timedelta64(1, 'D')
#sort values by column maturity
df = df.sort_values('maturity')
print df
    maturity  remain
4 2016-06-01      89
3 2016-10-01     211
2 2017-06-01     454
1 2017-10-01     576
0 2018-06-01     819

#get max count of years => loops
maxYears = (df['maturity'].max() - pd.to_datetime(d)) / np.timedelta64(1, 'D') / (365.25)
print maxYears
2.24229979466

#convert float to int,  if 2.999 => 2, so one year is added
#rather add one more year (leap years, year is only estimated)
maxYears = int(maxYears) + 2
print maxYears
4

我尝试估计循环的最大计数（未经深度测试）：

INSERT OVERWRITE TABLE All_three 
SELECT SYMBOL, VOLUME FROM First 
UNION 
SELECT SYMBOL, VOLUME FROM Middle 
UNION 
SELECT SYMBOL, VOLUME FROM Third;

减去数年的熊猫数据框并将其添加到矩阵中

1 个答案: