I want to know how to perform a resampling with a weighted average on each columns based on the time between each measurement. Here is an extract of the dataframe (the first column is in m³/h and the second in %): DEBITS VOLETS datetime 2014-01-21 00:03:03 NaN 49.93 2014-01-21 00:09:54 55.40 NaN 2014-01-21 00:12:59 NaN 47.72 2014-01-21 00:19:51 48.18 NaN 2014-01-21 00:22:57 NaN 49.44 2014-01-21 00:30:00 65.50 NaN 2014-01-21 00:33:04 NaN 49.37 2014-01-21 00:39:55 63.24 NaN 2014-01-21 00:43:00 NaN 49.69 2014-01-21 00:49:52 65.13 NaN 2014-01-21 00:52:57 NaN 48.75 2014-01-21 00:59:59 47.75 NaN 2014-01-21 01:03:05 NaN 48.50 2014-01-21 01:09:57 61.09 NaN 2014-01-21 01:13:01 NaN 48.16 2014-01-21 01:19:51 58.56 NaN 2014-01-21 01:22:57 NaN 50.09 2014-01-21 01:29:59 62.69 NaN 2014-01-21 01:33:04 NaN 48.55 2014-01-21 01:39:56 56.73 NaN 2014-01-21 01:43:01 NaN 49.06 2014-01-21 01:49:52 56.73 NaN 2014-01-21 01:52:57 NaN 48.73 2014-01-21 01:59:58 62.60 NaN I know I need to use a function as a parameter of "how" but I do not know how to articulate it. df.resample('H', how='mean') But I think the np.average of the numpy library function should be used, but NaN seems to cause an error. np.average(data['DEBITS'], weights=data.index) How to articulate this two function together to make this weighted average? Continue reading...