pandas.DataFrame.cummax#

DataFrame.cummax(axis=None,skipna=True,*args,**kwargs)[source]#

Return cumulative maximum over a DataFrame or Series axis.

Returns a DataFrame or Series of the same size containing the cumulativemaximum.

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’.ForSeries this parameter is unused and defaults to 0.

skipnabool, default True

Exclude NA/null values. If an entire row/column is NA, the resultwill be NA.

*args, **kwargs

Additional keywords have no effect but might be accepted forcompatibility with NumPy.

Returns:

Series or DataFrame

Return cumulative maximum of Series or DataFrame.

See also

core.window.expanding.Expanding.max

Similar functionality but ignoresNaN values.

DataFrame.max

Return the maximum 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])>>>s0    2.01    NaN2    5.03   -1.04    0.0dtype: float64

By default, NA values are ignored.

>>>s.cummax()0    2.01    NaN2    5.03    5.04    5.0dtype: float64

To include NA values in the operation, useskipna=False

>>>s.cummax(skipna=False)0    2.01    NaN2    NaN3    NaN4    NaNdtype: float64

DataFrame

>>>df=pd.DataFrame([[2.0,1.0],...[3.0,np.nan],...[1.0,0.0]],...columns=list('AB'))>>>df     A    B0  2.0  1.01  3.0  NaN2  1.0  0.0

By default, iterates over rows and finds the maximumin each column. This is equivalent toaxis=None oraxis='index'.

>>>df.cummax()     A    B0  2.0  1.01  3.0  NaN2  3.0  1.0

To iterate over columns and find the maximum in each row,useaxis=1

>>>df.cummax(axis=1)     A    B0  2.0  2.01  3.0  NaN2  1.0  1.0