What is the dot method in pandas?

The dot method in pandas takes the dot product of a dataframe with another dataframe, series, or array-like object. The dot product is also known as matrix multiplication.

The shapes of both objects should be compatible with each other to calculate the dot product.

The illustration below shows how the dot product is computed:

Syntax

The syntax of the dot method is as follows:

Dataframe.dot(other)

Parameters

The dot method has a single parameter: other.

Other refers to a dataframe, series, or array-like object with which the dot product is taken.

Return value

The dot method returns a series if the other parameter is a series object.

It returns a dataframe if the other parameter is a dataframe.

Examples

The code snippet below shows how we can use the dot operator in pandas:

import pandas as pd
import numpy as np
# Dataframe with a series
df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
s = pd.Series([1, 1, 2, 1])
print("Dataframe with a series")
print(df.dot(s))
print('\n')
# Dataframe with another Dataframe
other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
print("Dataframe with another Dataframe")
print(df.dot(other))
print('\n')
# Dataframe with an array
arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
print("Dataframe with another array")
print(df.dot(arr))
print('\n')