Pandas DataFrame How to query the closest datetime index?

Question

How do i query for the closest index from a Pandas DataFrame? The index is DatetimeIndex

2016-11-13 20:00:10.617989120   7.0 132.0 2016-11-13 22:00:00.022737152   1.0 128.0 2016-11-13 22:00:28.417561344   1.0 132.0 

I tried this:

df.index.get_loc(df.index[0], method='nearest') 

but it give me InvalidIndexError: Reindexing only valid with uniquely valued Index objects

Same error if I tried this:

dt = datetime.datetime.strptime("2016-11-13 22:01:25", "%Y-%m-%d %H:%M:%S") df.index.get_loc(dt, method='nearest') 

But if I remove method='nearest' it works, but that is not I want, I want to find the closest index from my query datetime

Answer 1

It seems you need first get position by get_loc and then select by []:

dt = pd.to_datetime("2016-11-13 22:01:25.450") print (dt) 2016-11-13 22:01:25.450000  print (df.index.get_loc(dt, method='nearest')) 2  idx = df.index[df.index.get_loc(dt, method='nearest')] print (idx) 2016-11-13 22:00:28.417561344 

#if need select row to Series use iloc s = df.iloc[df.index.get_loc(dt, method='nearest')] print (s) b      1.0 c    132.0 Name: 2016-11-13 22:00:28.417561344, dtype: float64