pandas.core.window.expanding.Expanding.first#

Expanding.first(numeric_only=False)[source]#

Calculate the expanding First (left-most) element of the window.

Parameters:

numeric_onlybool, default False

Include only float, int, boolean columns.

Added in version 1.5.0.

Returns:

Series or DataFrame

Return type is the same as the original object with np.float64 dtype.

See also

GroupBy.first

Similar method for GroupBy objects.

Expanding.last

Method to get the last element in each window.

Examples

The example below will show an expanding calculation with a window size of three.

>>> s = pd.Series(range(5))
>>> s.expanding(3).first()
0         NaN
1         NaN
2         0.0
3         0.0
4         0.0
dtype: float64