pluma.io.empatica.py, 'E4_Seconds' and 'Seconds' column dtype is <M8[ns], not datetime

[NeuroThom]

In pluma.io.empatica.py, parse_empatica_stream(), 'E4_Seconds' is used as a DatetimeIndex in one case:

pluma-analysis/pluma/io/empatica.py

Line 76 in d31bac2

df.index = pd.DatetimeIndex(df["E4_Seconds"] + clock_offset, name=df.index.name)

But has dtype of <M8[ns] in these cases:

pluma-analysis/pluma/io/empatica.py

Line 74 in d31bac2

df["E4_Seconds"] = _EMPATICA_T0 + pd.to_timedelta(df["E4_Seconds"].values.astype(float), "s")

pluma-analysis/pluma/io/empatica.py

Line 91 in d31bac2

df["E4_Seconds"] = _EMPATICA_T0 + pd.to_timedelta(df["E4_Seconds"].values.astype(float), "s")

Consider using pandas.datetime in these cases for consistency in data processing methods later, without the need to convert, for example to resample data using df = df.set_index('E4_seconds').resample("1S").mean().reset_index()

[glopesdev]

@NeuroThom sorry I was a bit confused in the end about which one you recommend we should use, is it pd.DatetimeIndex or pd.to_timedelta? From the text I am assuming it should be pd.DatetimeIndex but just wanted to be sure.

I believe the types in the lines you quoted might have been left there for backwards compatibility, or to provide access to unconverted raw data, not entirely sure. If clock_offset is defined, the conversion to pd.Datetime is already there. Expanding your two examples for context:

pluma-analysis/pluma/io/empatica.py

Lines 74 to 76 in d31bac2

	df["E4_Seconds"] = _EMPATICA_T0 + pd.to_timedelta(df["E4_Seconds"].values.astype(float), "s")
	if clock_offset is not None:
	df.index = pd.DatetimeIndex(df["E4_Seconds"] + clock_offset, name=df.index.name)

pluma-analysis/pluma/io/empatica.py

Lines 91 to 93 in d31bac2

	df["E4_Seconds"] = _EMPATICA_T0 + pd.to_timedelta(df["E4_Seconds"].values.astype(float), "s")
	if clock_offset is not None:
	df.index = pd.DatetimeIndex(df["E4_Seconds"] + clock_offset, name=df.index.name)

Is the recommendation that we simply define a default clock_offset, e.g. 0, if no known offset is provided? Not sure in which cases would a clock_offset not be defined.