我想在pandas数据框中创建一个新列，该列是从数据框开始起经过的时间。我正在将日志文件导入具有数据时间信息的数据帧，但是无法访问其中的total_seconds()功能s_df['delta_t']。如果我访问列（s_df['delta_t'].iloc[8].total_seconds()）的各个元素，则可以使用，但是我想用total_seconds（）创建一个新列，而我的尝试失败了。
total_seconds()
s_df['delta_t']
s_df['delta_t'].iloc[8].total_seconds()
s_df['t'] = s_df.index # s_df['t] is a column of datetime s_df['delta_t'] = ( s_df['t'] - s_df['t'].iloc[0]) # time since start of data frame s_df['elapsed_seconds'] = # want column s_df['delta_t'].total_seconds()
使用.dt访问器：
s_df['elapsed_seconds'] = s_df['delta_t'].dt.total_seconds()
例：
In [82]: df = pd.DataFrame({'date': pd.date_range(dt.datetime(2010,1,1), dt.datetime(2010,2,1))}) df['delta'] = df['date'] - df['date'].iloc[0] df Out[82]: date delta 0 2010-01-01 0 days 1 2010-01-02 1 days 2 2010-01-03 2 days 3 2010-01-04 3 days 4 2010-01-05 4 days 5 2010-01-06 5 days 6 2010-01-07 6 days 7 2010-01-08 7 days 8 2010-01-09 8 days 9 2010-01-10 9 days 10 2010-01-11 10 days 11 2010-01-12 11 days 12 2010-01-13 12 days 13 2010-01-14 13 days 14 2010-01-15 14 days 15 2010-01-16 15 days 16 2010-01-17 16 days 17 2010-01-18 17 days 18 2010-01-19 18 days 19 2010-01-20 19 days 20 2010-01-21 20 days 21 2010-01-22 21 days 22 2010-01-23 22 days 23 2010-01-24 23 days 24 2010-01-25 24 days 25 2010-01-26 25 days 26 2010-01-27 26 days 27 2010-01-28 27 days 28 2010-01-29 28 days 29 2010-01-30 29 days 30 2010-01-31 30 days 31 2010-02-01 31 days In [83]: df['total_seconds'] = df['delta'].dt.total_seconds() df Out[83]: date delta total_seconds 0 2010-01-01 0 days 0 1 2010-01-02 1 days 86400 2 2010-01-03 2 days 172800 3 2010-01-04 3 days 259200 4 2010-01-05 4 days 345600 5 2010-01-06 5 days 432000 6 2010-01-07 6 days 518400 7 2010-01-08 7 days 604800 8 2010-01-09 8 days 691200 9 2010-01-10 9 days 777600 10 2010-01-11 10 days 864000 11 2010-01-12 11 days 950400 12 2010-01-13 12 days 1036800 13 2010-01-14 13 days 1123200 14 2010-01-15 14 days 1209600 15 2010-01-16 15 days 1296000 16 2010-01-17 16 days 1382400 17 2010-01-18 17 days 1468800 18 2010-01-19 18 days 1555200 19 2010-01-20 19 days 1641600 20 2010-01-21 20 days 1728000 21 2010-01-22 21 days 1814400 22 2010-01-23 22 days 1900800 23 2010-01-24 23 days 1987200 24 2010-01-25 24 days 2073600 25 2010-01-26 25 days 2160000 26 2010-01-27 26 days 2246400 27 2010-01-28 27 days 2332800 28 2010-01-29 28 days 2419200 29 2010-01-30 29 days 2505600 30 2010-01-31 30 days 2592000 31 2010-02-01 31 days 2678400
