Calculate the expanding mean.
Include only float, int, boolean columns.
Added in version 1.5.0.
'cython' : Runs the operation through C-extensions from cython.
'numba' : Runs the operation through JIT compiled code from numba.
None : Defaults to 'cython' or globally setting compute.use_numba
Added in version 1.3.0.
For 'cython' engine, there are no accepted engine_kwargs
For 'numba' engine, the engine can accept nopython, nogil and parallel dictionary keys. The values must either be True or False. The default engine_kwargs for the 'numba' engine is {'nopython': True, 'nogil': False, 'parallel': False}
Added in version 1.3.0.
Return type is the same as the original object with np.float64 dtype.
See also
pandas.Series.expandingCalling expanding with Series data.
pandas.DataFrame.expandingCalling expanding with DataFrames.
pandas.Series.meanAggregating mean for Series.
pandas.DataFrame.meanAggregating mean for DataFrame.
Notes
See Numba engine and Numba (JIT compilation) for extended documentation and performance considerations for the Numba engine.
Examples
>>> ser = pd.Series([1, 2, 3, 4], index=['a', 'b', 'c', 'd'])
>>> ser.expanding().mean()
a 1.0
b 1.5
c 2.0
d 2.5
dtype: float64
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Licensed under the 3-clause BSD License.
https://pandas.pydata.org/pandas-docs/version/2.3.0/reference/api/pandas.core.window.expanding.Expanding.mean.html