pandas.stats.moments.expanding_count(arg, freq=None, center=False)

Expanding count of number of non-NaN observations.

Parameters :

arg : DataFrame or numpy ndarray-like

freq : string or DateOffset object, optional (default None)

Frequency to conform the data to before computing the statistic. Specified as a frequency string or DateOffset object.

center : boolean, default False

Whether the label should correspond with center of window.

Returns :

expanding_count : type of caller


The freq keyword is used to conform time series data to a specified frequency by resampling the data. This is done with the default parameters of resample() (i.e. using the mean).