
The cumsum() method in pandas return the cumulative sum over a DataFrame or Series axis. Each cell is populated with the cumulative sum of the values seen so far.
Syntax –
DataFrame.cumsum(axis=None, skipna=True, *args, **kwargs)
Examples –
Let’s create a dataframe to work with.
import pandas as pd
df = pd.DataFrame({'A': [1, 2, 3, 4, 5],
'B': [6, 7, 8, 9, 10]})
df

1 . Find the cumulative sum of the values seen so far along the index axis –
By default cumsum() method find the cumulative sum of the value seen so far in a column. You can also set it explicitly by setting the axis parameter to axis=0 or index.
df.cumsum(axis=0)

2 . Find the cumulative sum of the values seen so far along the column axis –
To find the cumulative sum of the value seen so far in a row we set the axis parameter to axis=1 or columns.
df.cumsum(axis=1)

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