pandas.DataFrame.cummin¶
- DataFrame.cummin(axis=None, skipna=True, *args, **kwargs)[source]¶
Return cumulative minimum over a DataFrame or Series axis.
Returns a DataFrame or Series of the same size containing the cumulative minimum.
- Parameters
- axis{0 or ‘index’, 1 or ‘columns’}, default 0
The index or the name of the axis. 0 is equivalent to None or ‘index’. For Series this parameter is unused and defaults to 0.
- skipnabool, default True
Exclude NA/null values. If an entire row/column is NA, the result will be NA.
- *args, **kwargs
Additional keywords have no effect but might be accepted for compatibility with NumPy.
- Returns
- Series or DataFrame
Return cumulative minimum of Series or DataFrame.
See also
core.window.expanding.Expanding.min
Similar functionality but ignores
NaN
values.DataFrame.min
Return the minimum over DataFrame axis.
DataFrame.cummax
Return cumulative maximum over DataFrame axis.
DataFrame.cummin
Return cumulative minimum over DataFrame axis.
DataFrame.cumsum
Return cumulative sum over DataFrame axis.
DataFrame.cumprod
Return cumulative product over DataFrame axis.
Examples
Series
>>> s = pd.Series([2, np.nan, 5, -1, 0]) >>> s 0 2.0 1 NaN 2 5.0 3 -1.0 4 0.0 dtype: float64
By default, NA values are ignored.
>>> s.cummin() 0 2.0 1 NaN 2 2.0 3 -1.0 4 -1.0 dtype: float64
To include NA values in the operation, use
skipna=False
>>> s.cummin(skipna=False) 0 2.0 1 NaN 2 NaN 3 NaN 4 NaN dtype: float64
DataFrame
>>> df = pd.DataFrame([[2.0, 1.0], ... [3.0, np.nan], ... [1.0, 0.0]], ... columns=list('AB')) >>> df A B 0 2.0 1.0 1 3.0 NaN 2 1.0 0.0
By default, iterates over rows and finds the minimum in each column. This is equivalent to
axis=None
oraxis='index'
.>>> df.cummin() A B 0 2.0 1.0 1 2.0 NaN 2 1.0 0.0
To iterate over columns and find the minimum in each row, use
axis=1
>>> df.cummin(axis=1) A B 0 2.0 1.0 1 3.0 NaN 2 1.0 0.0