Python - Replace values of a DataFrame with the value of another DataFrame in Pandas

To replace values of a DataFrame with the value of another DataFrame, use the replace() method n Pandas.

At first, let us first create a DataFrame −

dataFrame1 = pd.DataFrame({"Car": ["Audi", "Lamborghini"], "Place": ["US", "UK"], "Units": [200, 500]})

Let us create another DataFrame −

dataFrame2 = pd.DataFrame({"Car": ["BMW", "Lexus"], "Place": ["India", "Australia"], "Units": [800, 1000]})

Next, get a value from DataFrame2 and replace with a value from DataFrame1 −

# get value from 2nd DataFrame
i = dataFrame2['Car'][1]

# replacing with a value from the 1st DataFrame
j = dataFrame1['Car'][0]

Finally, use the replace() method to replace the value of one DataFrame with value of another DataFrame −

dataFrame2 = dataFrame2.replace(i, j)

Example

Following is the code −

import pandas as pd

dataFrame1 = pd.DataFrame({"Car": ["Audi", "Lamborghini"],"Place": ["US", "UK"], "Units": [200, 500]})

print("Dataframe 1...")
print(dataFrame1)

dataFrame2 = pd.DataFrame({"Car": ["BMW", "Lexus"],"Place": ["India", "Australia"], "Units": [800, 1000]})

print("\nDataframe 2...")
print(dataFrame2)

## Get a value from DataFrame2
## and replace with a value
## from DataFrame1

# getting value from 2nd DataFrame
i = dataFrame2['Car'][1]

# replacing with a value from the 1st DataFrame
j = dataFrame1['Car'][0]

# replace values of one DataFrame
# with the value of another DataFrame
dataFrame2 = dataFrame2.replace(i, j)

# Display the updated DataFrame
print("\nUpdated Dataframe 2...")
print(dataFrame2)

Output

This will produce the following output −

Dataframe 1...
     Car       Place   Units
0         Audi    US     200
1  Lamborghini    UK     500

Dataframe 2...
     Car       Place   Units
0    BMW       India     800
1  Lexus   Australia     1000

Updated Dataframe 2...
     Car       Place    Units
0   BMW        India      800
1  Audi    Australia   1000