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In Pandas, the sum of columns can be calculated using the sum() method, which allows you to pass in an axis argument to specify which axis you want to sum over (0 for the index, or 1 for the columns). This will then return a Series or DataFrame object, depending on the original data type. To get the sum of all the columns, you can just pass the argument axis=0. To get the sum of all the rows, you can pass the argument axis=1. Additionally, you can use the add() method to add two different columns together and store the result in a new column.
Often you may be interested in calculating the sum of one or more columns in a pandas DataFrame. Fortunately you can do this easily in pandas using the function.
This tutorial shows several examples of how to use this function.
Example 1: Find the Sum of a Single Column
Suppose we have the following pandas DataFrame:
import pandas as pd import numpy as np #create DataFrame df = pd.DataFrame({'rating': [90, 85, 82, 88, 94, 90, 76, 75, 87, 86], 'points': [25, 20, 14, 16, 27, 20, 12, 15, 14, 19], 'assists': [5, 7, 7, 8, 5, 7, 6, 9, 9, 5], 'rebounds': [np.nan, 8, 10, 6, 6, 9, 6, 10, 10, 7]}) #view DataFrame df rating points assists rebounds 0 90 25 5 NaN 1 85 20 7 8 2 82 14 7 10 3 88 16 8 6 4 94 27 5 6 5 90 20 7 9 6 76 12 6 6 7 75 15 9 10 8 87 14 9 10 9 86 19 5 7
We can find the sum of the column titled “points” by using the following syntax:
df['points'].sum()
182
The sum() function will also exclude NA’s by default. For example, if we find the sum of the “rebounds” column, the first value of “NaN” will simply be excluded from the calculation:
df['rebounds'].sum()
72.0
Example 2: Find the Sum of Multiple Columns
We can find the sum of multiple columns by using the following syntax:
#find sum of points and rebounds columns df[['rebounds', 'points']].sum() rebounds 72.0 points 182.0 dtype: float64
Example 3: Find the Sum of All Columns
We can find also find the sum of all columns by using the following syntax:
#find sum of all columns in DataFrame df.sum() rating 853.0 points 182.0 assists 68.0 rebounds 72.0 dtype: float64
For columns that are not numeric, the sum() function will simply not calculate the sum of those columns.
You can find the complete documentation for the sum() function .