expanding(min_periods=N).count(), for any N, returns same result as expanding(min_periods=1).count()

idx=pd.date_range('1/1/2019', periods=5)
s = pd.Series([2,3, np.nan, 10,20], index=idx)
s.expanding(min_periods=1).count()
s.expanding(min_periods=100).count()
s.expanding(min_periods=10000).count()

Problem description

They should not be returning the same results because the Series has only 5 records.

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Expected Output

Output of pd.show_versions()

[paste the output of pd.show_versions() here below this line]

[mroeschke]

That test isn’t exactly the same. For this issue, we need a test where min_periods > number of elements in the series

[theMogget]

take