Concatenate Pandas DataFrames Without Duplicates

In this article, we are going to concatenate two dataframes using pandas module.

In order to perform concatenation of two dataframes, we are going to use the pandas.concat().drop_duplicates() method in pandas module.

Step-by-step Approach: 

• Import module.
• Load two sample dataframes as variables.
• Concatenate the dataframes using pandas.concat().drop_duplicates() method.
• Display the new dataframe generated.

Below are some examples which depict how to perform concatenation between two dataframes using pandas module without duplicates:

Example 1:

Python3

# Importing pandas library
import pandas as pd

# loading dataframes
dataframe1 = pd.DataFrame({'columnA': [20, 30, 40],
                           'columnB': [200, 300, 400]})

dataframe2 = pd.DataFrame({'columnA': [50, 20, 60],
                           'columnB': [500, 200, 600]})

# Concatenating dataframes without duplicates
new_dataframe = pd.concat([dataframe1, dataframe2]).drop_duplicates()

# Display concatenated dataframe
new_dataframe

Output:

Here, we have concatenated two dataframes using pandas.concat() method.

Example 2:

Python3

# Importing pandas library
import pandas as pd

# loading dataframes
dataframe1 = pd.DataFrame({'name': ['rahul', 'anjali', 'kajal'],
                           'age': [23, 28, 30]})

dataframe2 = pd.DataFrame({'name': ['devesh', 'rashi', 'anjali'],
                           'age': [20, 15, 28]})

# Concatenating two dataframes without duplicates
new_dataframe = pd.concat([dataframe1, dataframe2]).drop_duplicates()

# Resetting index
new_dataframe = new_dataframe.reset_index(drop=True)

# Display dataframe generated
new_dataframe

Output:

As shown in the output image, we get the concatenation of dataframes without removing duplicates.

Example 3:

Python3

# Importing pandas library
import pandas as pd

# Loading dataframes
dataframe1 = pd.DataFrame({'empname': ['rohan', 'hina', 'alisa', ],
                           'department': ['IT', 'admin', 'finance', ],
                           'designation': ['Sr.developer', 'administrator', 'executive', ]})

dataframe2 = pd.DataFrame({'empname': ['rishi', 'huma', 'alisa', ],
                           'department': ['cyber security', 'HR', 'finance', ],
                           'designation': ['penetration tester', 'HR executive', 'executive', ]})

# Concatenating two dataframes without duplicates
new_dataframe = pd.concat([dataframe1, dataframe2]).drop_duplicates()

# Resetting index
new_dataframe = new_dataframe.reset_index(drop=True)

# Display dataframe generated
new_dataframe

Output:

Here is another example, which depicts how to concatenate two dataframes.

Output dataset for the Example 3