JIYIK CN >

Python Pandas DataFrame.sum() function calculates the DataFramesum of the values ​​of the object along the specified axis.

pandas.DataFrame.sum()Syntax

DataFrame.sum(
    axis=None, skipna=None, level=None, numeric_only=None, min_count=0, **kwargs
)

parameter

Return Value

If not specified level, returns the sum of the values ​​along the requested axis Series, otherwise returns the sum of the values DataFrame.

Example code: DataFrame.sum()Method to calculate sum along column axis

import pandas as pd

df = pd.DataFrame({'X': 
                   [1,2,3,4,5], 
                   'Y': [1, 2, 3,4,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sums=df.sum()
print("Column-wise Sum:")
print(sums)

Output:

DataFrame:
   X  Y  Z
0  1  1  3
1  2  2  4
2  3  3  5
3  4  4  6
4  5  5  3
Column-wise Sum:
X    15
Y    15
Z    21
dtype: int64

It calculates the sum of all columns X, Yand Z, and finally returns a Seriesobject that includes the sum of each column.

In Pandas, to find the sum of a column in a DataFrame, you just need to call sum()the sum function on that column.

import pandas as pd

df = pd.DataFrame({'X': 
                   [1,2,3,4,5], 
                   'Y': [1, 2, 3,4,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sums=df["Z"].sum()
print("Sum of values of Z-column:")
print(sums)

Output:

DataFrame:
   X  Y  Z
0  1  1  3
1  2  2  4
2  3  3  5
3  4  4  6
4  5  5  3
Sum of values of Z-column:
21

It just gives Zthe sum of the DataFrame column values.

Example Code: DataFrame.sum()Method to Find Sum Along Row Axis

import pandas as pd

df = pd.DataFrame({'X': 
                   [1,2,3,4,5], 
                   'Y': [1, 2, 3,4,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sums=df.sum(axis=1)
print("Row-wise sum:")
print(sums)

Output:

DataFrame:
   X  Y  Z
0  1  1  3
1  2  2  4
2  3  3  5
3  4  4  6
4  5  5  3
Row-wise sum:
0     5
1     8
2    11
3    14
4    13
dtype: int64

It calculates the sum of all rows and returns a Seriesobject containing the sum for each row.

In Pandas, if you want to find DataFramethe sum of a row in , you need to call sum()the function to calculate the sum of that row.

import pandas as pd

df = pd.DataFrame({'X': 
                   [1,2,3,4,5], 
                   'Y': [1, 2, 3,4,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sum_3=df.iloc[[2]].sum(axis=1)
print("Sum of values of 3rd Row:")
print(sum_3)

Output:

DataFrame:
   X  Y  Z
0  1  1  3
1  2  2  4
2  3  3  5
3  4  4  6
4  5  5  3
Sum of values of 3rd Row:
2    11
dtype: int64

It only gives DataFramethe sum of the values ​​in the third row of .

Use ilocthe method to select a row based on its index.

Example code: DataFrame.sum()Method lookup ignoring NaNthe sum of values

Uses skipnathe default value of the parameter, which skipna=Truefinds the sum of along the specified axis DataFrameand ignores NaNthe value of .

import pandas as pd
df = pd.DataFrame({'X': 
                   [1,None,3,4,5], 
                   'Y': [1, None, 3,None,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sums=df.sum()
print("Column-wise Sum:")
print(sums)

Output:

DataFrame:
     X    Y  Z
0  1.0  1.0  3
1  NaN  NaN  4
2  3.0  3.0  5
3  4.0  NaN  6
4  5.0  5.0  3
Column-wise Sum:
X    13.0
Y     9.0
Z    21.0
dtype: float64

If you set skipna=True, if the DataFrame has NaNvalues, you will get NaNthe sum of the values.

import pandas as pd

df = pd.DataFrame({'X': 
                   [1,None,3,4,5], 
                   'Y': [1, None, 3,None,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sums=df.sum(skipna=False)
print("Column-wise Sum:")
print(sums)

Output:

DataFrame:
     X    Y  Z
0  1.0  1.0  3
1  NaN  NaN  4
2  3.0  3.0  5
3  4.0  NaN  6
4  5.0  5.0  3
Column-wise Sum:
X     NaN
Y     NaN
Z    21.0
dtype: float64

Here, you get the value of the sum Xof columns Yand NaN, since they both have NaNvalues.

Sample code: DataFrame.sum()Set in the methodmin_count

import pandas as pd

df = pd.DataFrame({'X': 
                   [1,None,3,4,5], 
                   'Y': [1, None, 3,None,5], 
                   'Z': [3,4,5,6,3]})
print("DataFrame:")
print(df)

sums=df.sum(min_count=4)
print("Column-wise Sum:")
print(sums)

Output:

DataFrame:
     X    Y  Z
0  1.0  1.0  3
1  NaN  NaN  4
2  3.0  3.0  5
3  4.0  NaN  6
4  5.0  5.0  3
Column-wise Sum:
X    13.0
Y     NaN
Z    21.0
dtype: float64

Here, you can get the value Yof the sum of the column NaNbecause Ythe column has only 3 non- NaNvalues, which is less than min_countthe value of the parameter.