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pythonpandasdataframerowfill

fill each row of a dataframe with zero starting from the column in which the values decreases with respect to the value in the previous column


I would like to fill each row of a dataframe with zero starting from the column in which the value decreases with respect to the value in the previous column

I have the following Dataframe:

ActualDf = pd.DataFrame(np.array([[2, 3, 2, 3, 4, 5, 0, 0, 0, 0, 0], [1, 1, 1, 2, 2, 3, 1, 1, 0, 0, 0], [2, 2, 2, 3, 3, 5, 3, 3, 0, 0, 0], [2, 3, 2, 3, 3, 3, 4, 1, 2, 0, 0], [3, 3, 1, 2, 2, 5, 0, 0, 0, 0, 0], [1, 2, 3, 1, 2, 3, 0, 0, 0, 0, 0]]),
columns=['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10']

)

And I would like to obtain this one

DesiredDf = pd.DataFrame(np.array([[2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0], [1, 1, 1, 2, 2, 3, 0, 0, 0, 0, 0], [2, 2, 2, 3, 3, 5, 0, 0, 0, 0, 0], [2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0], [3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0], [1, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0]]),
columns=['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10'])

How is it possible to da that in an efficient way?


Solution

  • You could use diff and lt to find where the difference is negative, and then use cumsum and gt to flag all cells after the first negative value.

    ActualDf[ActualDf.diff(axis=1).lt(0).cumsum(1).gt(0)] = 0