我已经看过Panda Timeseries这样做了，但希望得到一些Dataframes的帮助。我有一个1966-2009的月度值文件。我没有1985年的数据，也想添加2010/2011的数据。这些添加物只会附加NaN。
使用下面的代码，我试图剪切我的数据集，使其从1980年开始，然后在附加NaN值时缺少的年份中添加。但是，没有任何东西被削减，也没有添加任我有什么遗失的东西吗？
idx = pd.date_range('01-01-1980','12-31-2011',freq='M')
years = np.arange(1980,2012,1)
obdata = pd.read_table('H:/Dissertation/Data/Observations/'+str(int(statid[e]))+'.txt',index_col='datetime',parse_dates={'datetime':[3,4]},date_parser=lambda x: pd.datetime.strptime(x, '%Y %m'),keep_date_col='True')
o_d = obdata.loc[obdata['Year'].isin(years)]
o_d['sd'] = np.nan_to_num(o_d['sd'])
o_d.reindex(idx,fill_value='NaN')
grouped_same.append(o_d['sd'])
现在提供了一些示例数据。正如你所看到的，1985年缺失，数据在2009年停止。我将把所有的NaN变成0，我想用“sd”填充缺失的月度数据。作为NaN。
ID Lat Lon Year Month sd
32539 53.12 157.75 1978 1 127.00
32539 53.12 157.75 1978 2 150.00
32539 53.12 157.75 1978 3 152.00
32539 53.12 157.75 1978 4 139.00
32539 53.12 157.75 1978 5 63.00
32539 53.12 157.75 1978 6 NaN
32539 53.12 157.75 1978 7 NaN
32539 53.12 157.75 1978 8 NaN
32539 53.12 157.75 1978 9 NaN
32539 53.12 157.75 1978 10 2.00
32539 53.12 157.75 1978 11 17.50
32539 53.12 157.75 1978 12 79.00
32539 53.12 157.75 1979 1 72.00
32539 53.12 157.75 1979 2 113.00
32539 53.12 157.75 1979 3 129.00
32539 53.12 157.75 1979 4 109.67
32539 53.12 157.75 1979 5 51.00
32539 53.12 157.75 1979 6 NaN
32539 53.12 157.75 1979 7 NaN
32539 53.12 157.75 1979 8 NaN
32539 53.12 157.75 1979 9 NaN
32539 53.12 157.75 1979 10 22.50
32539 53.12 157.75 1979 11 68.67
32539 53.12 157.75 1979 12 90.00
32539 53.12 157.75 1980 1 183.00
32539 53.12 157.75 1980 2 217.00
32539 53.12 157.75 1980 3 218.00
32539 53.12 157.75 1980 4 201.50
32539 53.12 157.75 1980 5 133.67
32539 53.12 157.75 1980 6 32.00
32539 53.12 157.75 1980 7 NaN
32539 53.12 157.75 1980 8 NaN
32539 53.12 157.75 1980 9 NaN
32539 53.12 157.75 1980 10 20.50
32539 53.12 157.75 1980 11 56.67
32539 53.12 157.75 1980 12 78.33
32539 53.12 157.75 1981 1 108.33
32539 53.12 157.75 1981 2 125.33
32539 53.12 157.75 1981 3 124.00
32539 53.12 157.75 1981 4 108.67
32539 53.12 157.75 1981 5 42.00
32539 53.12 157.75 1981 6 NaN
32539 53.12 157.75 1981 7 NaN
32539 53.12 157.75 1981 8 NaN
32539 53.12 157.75 1981 9 NaN
32539 53.12 157.75 1981 10 16.00
32539 53.12 157.75 1981 11 38.67
32539 53.12 157.75 1981 12 66.33
32539 53.12 157.75 1982 1 94.33
32539 53.12 157.75 1982 2 131.33
32539 53.12 157.75 1982 3 127.33
32539 53.12 157.75 1982 4 101.33
32539 53.12 157.75 1982 5 29.33
32539 53.12 157.75 1982 6 NaN
32539 53.12 157.75 1982 7 NaN
32539 53.12 157.75 1982 8 NaN
32539 53.12 157.75 1982 9 NaN
32539 53.12 157.75 1982 10 12.50
32539 53.12 157.75 1982 11 28.33
32539 53.12 157.75 1982 12 66.67
32539 53.12 157.75 1983 1 108.33
32539 53.12 157.75 1983 2 121.33
32539 53.12 157.75 1983 3 133.67
32539 53.12 157.75 1983 4 128.33
32539 53.12 157.75 1983 5 66.00
32539 53.12 157.75 1983 6 NaN
32539 53.12 157.75 1983 7 NaN
32539 53.12 157.75 1983 8 NaN
32539 53.12 157.75 1983 9 NaN
32539 53.12 157.75 1983 10 11.00
32539 53.12 157.75 1983 11 35.33
32539 53.12 157.75 1983 12 72.00
32539 53.12 157.75 1984 1 87.33
32539 53.12 157.75 1984 2 163.00
32539 53.12 157.75 1984 3 185.00
32539 53.12 157.75 1984 4 154.33
32539 53.12 157.75 1984 5 79.00
32539 53.12 157.75 1984 6 NaN
32539 53.12 157.75 1984 7 NaN
32539 53.12 157.75 1984 8 NaN
32539 53.12 157.75 1984 9 NaN
32539 53.12 157.75 1984 10 NaN
32539 53.12 157.75 1984 11 44.67
32539 53.12 157.75 1984 12 76.33
32539 53.12 157.75 1986 1 148.33
32539 53.12 157.75 1986 2 160.00
32539 53.12 157.75 1986 3 178.00
32539 53.12 157.75 1986 4 131.00
32539 53.12 157.75 1986 5 61.33
32539 53.12 157.75 1986 6 NaN
32539 53.12 157.75 1986 7 NaN
32539 53.12 157.75 1986 8 NaN
32539 53.12 157.75 1986 9 NaN
32539 53.12 157.75 1986 10 NaN
32539 53.12 157.75 1986 11 NaN
32539 53.12 157.75 1986 12 NaN
32539 53.12 157.75 1987 1 73.00
32539 53.12 157.75 1987 2 102.67
32539 53.12 157.75 1987 3 142.33
32539 53.12 157.75 1987 4 128.33
32539 53.12 157.75 1987 5 75.50
32539 53.12 157.75 1987 6 NaN
32539 53.12 157.75 1987 7 NaN
32539 53.12 157.75 1987 8 NaN
32539 53.12 157.75 1987 9 NaN
32539 53.12 157.75 1987 10 19.00
32539 53.12 157.75 1987 11 56.67
32539 53.12 157.75 1987 12 84.50
32539 53.12 157.75 1988 1 98.33
32539 53.12 157.75 1988 2 120.33
32539 53.12 157.75 1988 3 144.67
32539 53.12 157.75 1988 4 134.33
32539 53.12 157.75 1988 5 70.33
32539 53.12 157.75 1988 6 NaN
32539 53.12 157.75 1988 7 NaN
32539 53.12 157.75 1988 8 NaN
32539 53.12 157.75 1988 9 NaN
32539 53.12 157.75 1988 10 NaN
32539 53.12 157.75 1988 11 58.67
32539 53.12 157.75 1988 12 109.67
32539 53.12 157.75 1989 1 113.00
32539 53.12 157.75 1989 2 156.00
32539 53.12 157.75 1989 3 181.00
32539 53.12 157.75 1989 4 168.00
32539 53.12 157.75 1989 5 NaN
32539 53.12 157.75 1989 6 NaN
32539 53.12 157.75 1989 7 NaN
32539 53.12 157.75 1989 8 NaN
32539 53.12 157.75 1989 9 NaN
32539 53.12 157.75 1989 10 8.00
32539 53.12 157.75 1989 11 46.00
32539 53.12 157.75 1989 12 92.67
32539 53.12 157.75 1990 1 102.67
32539 53.12 157.75 1990 2 131.67
32539 53.12 157.75 1990 3 153.50
32539 53.12 157.75 1990 4 132.00
32539 53.12 157.75 1990 5 53.25
32539 53.12 157.75 1990 6 NaN
32539 53.12 157.75 1990 7 NaN
32539 53.12 157.75 1990 8 NaN
32539 53.12 157.75 1990 9 NaN
32539 53.12 157.75 1990 10 NaN
32539 53.12 157.75 1990 11 28.00
32539 53.12 157.75 1990 12 56.00
32539 53.12 157.75 1991 1 83.33
32539 53.12 157.75 1991 2 118.00
32539 53.12 157.75 1991 3 118.00
32539 53.12 157.75 1991 4 127.67
32539 53.12 157.75 1991 5 69.50
32539 53.12 157.75 1991 6 NaN
32539 53.12 157.75 1991 7 NaN
32539 53.12 157.75 1991 8 NaN
32539 53.12 157.75 1991 9 NaN
32539 53.12 157.75 1991 10 18.00
32539 53.12 157.75 1991 11 27.00
32539 53.12 157.75 1991 12 56.00
32539 53.12 157.75 1992 1 62.00
32539 53.12 157.75 1992 2 107.00
32539 53.12 157.75 1992 3 133.67
32539 53.12 157.75 1992 4 122.67
32539 53.12 157.75 1992 5 74.25
32539 53.12 157.75 1992 6 NaN
32539 53.12 157.75 1992 7 NaN
32539 53.12 157.75 1992 8 NaN
32539 53.12 157.75 1992 9 NaN
32539 53.12 157.75 1992 10 3.00
32539 53.12 157.75 1992 11 33.33
32539 53.12 157.75 1992 12 64.33
32539 53.12 157.75 1993 1 80.67
32539 53.12 157.75 1993 2 96.00
32539 53.12 157.75 1993 3 101.67
32539 53.12 157.75 1993 4 120.00
32539 53.12 157.75 1993 5 78.33
32539 53.12 157.75 1993 6 NaN
32539 53.12 157.75 1993 7 NaN
32539 53.12 157.75 1993 8 NaN
32539 53.12 157.75 1993 9 NaN
32539 53.12 157.75 1993 10 10.00
32539 53.12 157.75 1993 11 36.67
32539 53.12 157.75 1993 12 81.00
32539 53.12 157.75 1994 1 125.00
32539 53.12 157.75 1994 2 209.00
32539 53.12 157.75 1994 3 199.00
32539 53.12 157.75 1994 4 205.00
32539 53.12 157.75 1994 5 132.00
32539 53.12 157.75 1994 6 49.00
32539 53.12 157.75 1994 7 NaN
32539 53.12 157.75 1994 8 NaN
32539 53.12 157.75 1994 9 NaN
32539 53.12 157.75 1994 10 3.00
32539 53.12 157.75 1994 11 34.33
32539 53.12 157.75 1994 12 61.00
32539 53.12 157.75 1995 1 76.33
32539 53.12 157.75 1995 2 96.00
32539 53.12 157.75 1995 3 125.33
32539 53.12 157.75 1995 4 142.00
32539 53.12 157.75 1995 5 43.75
32539 53.12 157.75 1995 6 NaN
32539 53.12 157.75 1995 7 NaN
32539 53.12 157.75 1995 8 NaN
32539 53.12 157.75 1995 9 NaN
32539 53.12 157.75 1995 10 NaN
32539 53.12 157.75 1995 11 34.67
32539 53.12 157.75 1995 12 55.67
32539 53.12 157.75 1996 1 142.50
32539 53.12 157.75 1996 2 162.00
32539 53.12 157.75 1996 3 152.00
32539 53.12 157.75 1996 4 191.00
32539 53.12 157.75 1996 5 85.33
32539 53.12 157.75 1996 6 NaN
32539 53.12 157.75 1996 7 NaN
32539 53.12 157.75 1996 8 NaN
32539 53.12 157.75 1996 9 NaN
32539 53.12 157.75 1996 10 4.00
32539 53.12 157.75 1996 11 41.00
32539 53.12 157.75 1996 12 99.00
32539 53.12 157.75 1997 1 185.00
32539 53.12 157.75 1997 2 232.00
32539 53.12 157.75 1997 3 239.00
32539 53.12 157.75 1997 4 218.00
32539 53.12 157.75 1997 5 141.50
32539 53.12 157.75 1997 6 43.00
32539 53.12 157.75 1997 7 NaN
32539 53.12 157.75 1997 8 NaN
32539 53.12 157.75 1997 9 NaN
32539 53.12 157.75 1997 10 NaN
32539 53.12 157.75 1997 11 29.00
32539 53.12 157.75 1997 12 80.33
32539 53.12 157.75 1998 1 121.33
32539 53.12 157.75 1998 2 130.33
32539 53.12 157.75 1998 3 127.00
32539 53.12 157.75 1998 4 123.67
32539 53.12 157.75 1998 5 85.67
32539 53.12 157.75 1998 6 NaN
32539 53.12 157.75 1998 7 NaN
32539 53.12 157.75 1998 8 NaN
32539 53.12 157.75 1998 9 NaN
32539 53.12 157.75 1998 10 26.00
32539 53.12 157.75 1998 11 45.67
32539 53.12 157.75 1998 12 78.33
32539 53.12 157.75 1999 1 132.50
32539 53.12 157.75 1999 2 142.00
32539 53.12 157.75 1999 3 168.00
32539 53.12 157.75 1999 4 150.50
32539 53.12 157.75 1999 5 77.33
32539 53.12 157.75 1999 6 NaN
32539 53.12 157.75 1999 7 NaN
32539 53.12 157.75 1999 8 NaN
32539 53.12 157.75 1999 9 NaN
32539 53.12 157.75 1999 10 7.00
32539 53.12 157.75 1999 11 43.33
32539 53.12 157.75 1999 12 83.67
32539 53.12 157.75 2000 1 90.00
32539 53.12 157.75 2000 2 94.00
32539 53.12 157.75 2000 3 98.00
32539 53.12 157.75 2000 4 91.00
32539 53.12 157.75 2000 5 48.00
32539 53.12 157.75 2000 6 NaN
32539 53.12 157.75 2000 7 NaN
32539 53.12 157.75 2000 8 NaN
32539 53.12 157.75 2000 9 NaN
32539 53.12 157.75 2000 10 34.00
32539 53.12 157.75 2000 11 56.67
32539 53.12 157.75 2000 12 67.67
32539 53.12 157.75 2002 1 130.67
32539 53.12 157.75 2002 2 121.00
32539 53.12 157.75 2002 3 136.00
32539 53.12 157.75 2002 4 151.50
32539 53.12 157.75 2002 5 51.00
32539 53.12 157.75 2002 6 NaN
32539 53.12 157.75 2002 7 NaN
32539 53.12 157.75 2002 8 NaN
32539 53.12 157.75 2002 9 NaN
32539 53.12 157.75 2002 10 12.50
32539 53.12 157.75 2002 11 23.33
32539 53.12 157.75 2002 12 48.33
32539 53.12 157.75 2003 1 71.00
32539 53.12 157.75 2003 2 91.67
32539 53.12 157.75 2003 3 105.00
32539 53.12 157.75 2003 4 100.67
32539 53.12 157.75 2003 5 61.00
32539 53.12 157.75 2003 6 NaN
32539 53.12 157.75 2003 7 NaN
32539 53.12 157.75 2003 8 NaN
32539 53.12 157.75 2003 9 NaN
32539 53.12 157.75 2003 10 NaN
32539 53.12 157.75 2003 11 34.33
32539 53.12 157.75 2003 12 76.33
32539 53.12 157.75 2004 1 109.00
32539 53.12 157.75 2004 2 128.33
32539 53.12 157.75 2004 3 138.33
32539 53.12 157.75 2004 4 127.50
32539 53.12 157.75 2004 5 66.67
32539 53.12 157.75 2004 6 NaN
32539 53.12 157.75 2004 7 NaN
32539 53.12 157.75 2004 8 NaN
32539 53.12 157.75 2004 9 NaN
32539 53.12 157.75 2004 10 6.50
32539 53.12 157.75 2004 11 52.00
32539 53.12 157.75 2004 12 105.67
32539 53.12 157.75 2005 1 156.00
32539 53.12 157.75 2005 2 205.00
32539 53.12 157.75 2005 3 273.00
32539 53.12 157.75 2005 4 216.00
32539 53.12 157.75 2005 5 117.00
32539 53.12 157.75 2005 6 41.00
32539 53.12 157.75 2005 7 NaN
32539 53.12 157.75 2005 8 NaN
32539 53.12 157.75 2005 9 NaN
32539 53.12 157.75 2005 10 10.00
32539 53.12 157.75 2005 11 38.00
32539 53.12 157.75 2005 12 108.00
32539 53.12 157.75 2006 1 191.50
32539 53.12 157.75 2006 2 199.00
32539 53.12 157.75 2006 3 195.00
32539 53.12 157.75 2006 4 209.00
32539 53.12 157.75 2006 5 109.50
32539 53.12 157.75 2006 6 44.50
32539 53.12 157.75 2006 7 NaN
32539 53.12 157.75 2006 8 NaN
32539 53.12 157.75 2006 9 NaN
32539 53.12 157.75 2006 10 9.00
32539 53.12 157.75 2006 11 8.33
32539 53.12 157.75 2006 12 27.33
32539 53.12 157.75 2007 1 54.33
32539 53.12 157.75 2007 2 67.67
32539 53.12 157.75 2007 3 145.67
32539 53.12 157.75 2007 4 124.00
32539 53.12 157.75 2007 5 55.00
32539 53.12 157.75 2007 6 NaN
32539 53.12 157.75 2007 7 NaN
32539 53.12 157.75 2007 8 NaN
32539 53.12 157.75 2007 9 16.00
32539 53.12 157.75 2007 10 1.50
32539 53.12 157.75 2007 11 36.00
32539 53.12 157.75 2007 12 74.00
32539 53.12 157.75 2008 1 119.67
32539 53.12 157.75 2008 2 125.50
32539 53.12 157.75 2008 3 153.00
32539 53.12 157.75 2008 4 124.00
32539 53.12 157.75 2008 5 43.25
32539 53.12 157.75 2008 6 NaN
32539 53.12 157.75 2008 7 NaN
32539 53.12 157.75 2008 8 NaN
32539 53.12 157.75 2008 9 NaN
32539 53.12 157.75 2008 10 16.00
32539 53.12 157.75 2008 11 56.00
32539 53.12 157.75 2008 12 103.00
32539 53.12 157.75 2009 1 NaN
32539 53.12 157.75 2009 2 181.00
32539 53.12 157.75 2009 3 190.00
32539 53.12 157.75 2009 4 175.00
32539 53.12 157.75 2009 5 81.00
32539 53.12 157.75 2009 6 NaN
32539 53.12 157.75 2009 7 NaN
32539 53.12 157.75 2009 8 NaN
32539 53.12 157.75 2009 9 NaN
32539 53.12 157.75 2009 10 14.00
32539 53.12 157.75 2009 11 43.67
32539 53.12 157.75 2009 12 79.00
答案 0 :(得分：1)
我认为通过to_period转换periodindex可以更好地使用datetimeindex。
您可以在sd栏中0到np.nan，并使用fillna填写import pandas as pd
import numpy as np
obdata = pd.read_csv('H:/Dissertation/Data/Observations/'+str(int(statid[e]))+'.txt', index_col='datetime', parse_dates={'datetime':[3,4]},date_parser=lambda x: pd.datetime.strptime(x, '%Y %m'),keep_date_col='True')
#print obdata.head(100)
#convert string column Year to int (maybe you can omit it)
obdata['Year'] = obdata['Year'].astype(int)
#change datetimeindex to periodindex
idx = pd.date_range('01-01-1980','12-01-2011',freq='M').to_period('m')
years = np.arange(1980,2012,1)
#change datetimeindex to periodindex
obdata.index = obdata.index.to_period('m')
#fill NaN to 0 in column sd
obdata['sd'] = obdata['sd'].fillna(0)
o_d = obdata.loc[obdata['Year'].isin(years)]
#reindex and add NaN
o_d = o_d.reindex(idx,fill_value=np.nan)
。
ID Lat Lon Year Month sd
1980-01 32539 53.12 157.75 1980 1 183.00
1980-02 32539 53.12 157.75 1980 2 217.00
1980-03 32539 53.12 157.75 1980 3 218.00
1980-04 32539 53.12 157.75 1980 4 201.50
1980-05 32539 53.12 157.75 1980 5 133.67
1980-06 32539 53.12 157.75 1980 6 32.00
1980-07 32539 53.12 157.75 1980 7 0.00
1980-08 32539 53.12 157.75 1980 8 0.00
1980-09 32539 53.12 157.75 1980 9 0.00
1980-10 32539 53.12 157.75 1980 10 20.50
1980-11 32539 53.12 157.75 1980 11 56.67
1980-12 32539 53.12 157.75 1980 12 78.33
1981-01 32539 53.12 157.75 1981 1 108.33
1981-02 32539 53.12 157.75 1981 2 125.33
1981-03 32539 53.12 157.75 1981 3 124.00
1981-04 32539 53.12 157.75 1981 4 108.67
1981-05 32539 53.12 157.75 1981 5 42.00
1981-06 32539 53.12 157.75 1981 6 0.00
1981-07 32539 53.12 157.75 1981 7 0.00
1981-08 32539 53.12 157.75 1981 8 0.00
1981-09 32539 53.12 157.75 1981 9 0.00
1981-10 32539 53.12 157.75 1981 10 16.00
1981-11 32539 53.12 157.75 1981 11 38.67
1981-12 32539 53.12 157.75 1981 12 66.33
1982-01 32539 53.12 157.75 1982 1 94.33
1982-02 32539 53.12 157.75 1982 2 131.33
1982-03 32539 53.12 157.75 1982 3 127.33
1982-04 32539 53.12 157.75 1982 4 101.33
1982-05 32539 53.12 157.75 1982 5 29.33
1982-06 32539 53.12 157.75 1982 6 0.00
... ... ... ... ... ... ...
1984-03 32539 53.12 157.75 1984 3 185.00
1984-04 32539 53.12 157.75 1984 4 154.33
1984-05 32539 53.12 157.75 1984 5 79.00
1984-06 32539 53.12 157.75 1984 6 0.00
1984-07 32539 53.12 157.75 1984 7 0.00
1984-08 32539 53.12 157.75 1984 8 0.00
1984-09 32539 53.12 157.75 1984 9 0.00
1984-10 32539 53.12 157.75 1984 10 0.00
1984-11 32539 53.12 157.75 1984 11 44.67
1984-12 32539 53.12 157.75 1984 12 76.33
1985-01 NaN NaN NaN NaN NaN NaN
1985-02 NaN NaN NaN NaN NaN NaN
1985-03 NaN NaN NaN NaN NaN NaN
1985-04 NaN NaN NaN NaN NaN NaN
1985-05 NaN NaN NaN NaN NaN NaN
1985-06 NaN NaN NaN NaN NaN NaN
1985-07 NaN NaN NaN NaN NaN NaN
1985-08 NaN NaN NaN NaN NaN NaN
1985-09 NaN NaN NaN NaN NaN NaN
1985-10 NaN NaN NaN NaN NaN NaN
1985-11 NaN NaN NaN NaN NaN NaN
1985-12 NaN NaN NaN NaN NaN NaN
1986-01 32539 53.12 157.75 1986 1 148.33
1986-02 32539 53.12 157.75 1986 2 160.00
1986-03 32539 53.12 157.75 1986 3 178.00
1986-04 32539 53.12 157.75 1986 4 131.00
1986-05 32539 53.12 157.75 1986 5 61.33
1986-06 32539 53.12 157.75 1986 6 0.00
1986-07 32539 53.12 157.75 1986 7 0.00
1986-08 32539 53.12 157.75 1986 8 0.00
print o_d.head(80)
encrypted_message=''
for character in message:
if character != ' ':
encrypted_message += encrypt(character)
else:
encrypted_message += character
print encrypted_messsage