Write a Python code to filter palindrome names in a given dataframe

A palindrome is a word that reads the same forwards and backwards. In this tutorial, we'll learn how to filter palindrome names from a Pandas DataFrame using different approaches.

Using List Comprehension

This approach uses list comprehension to identify palindromes by comparing each name with its reverse using slicing [::-1] ?

import pandas as pd

data = {'Id': [1, 2, 3, 4, 5], 'Name': ['bob', 'peter', 'hannah', 'james', 'david']}
df = pd.DataFrame(data)
print("DataFrame is:")
print(df)

# Find palindrome names using list comprehension
palindromes = [name for name in df['Name'] if name == name[::-1]]
result = df[df['Name'].isin(palindromes)]
print("\nPalindrome names are:")
print(result)

DataFrame is:
   Id    Name
0   1     bob
1   2   peter
2   3  hannah
3   4   james
4   5   david

Palindrome names are:
   Id    Name
0   1     bob
2   3  hannah

Using Lambda Function with Filter

This approach uses a lambda function with filter() to check if each name equals its reversed version using reversed() ?

import pandas as pd

data = {'Id': [1, 2, 3, 4, 5], 'Name': ['bob', 'peter', 'hannah', 'james', 'david']}
df = pd.DataFrame(data)
print("DataFrame is:")
print(df)

# Find palindrome names using filter with lambda
palindromes = list(filter(lambda x: (x == "".join(reversed(x))), df['Name']))
result = df[df['Name'].isin(palindromes)]
print("\nPalindrome names are:")
print(result)

DataFrame is:
   Id    Name
0   1     bob
1   2   peter
2   3  hannah
3   4   james
4   5   david

Palindrome names are:
   Id    Name
0   1     bob
2   3  hannah

Using Direct Boolean Indexing

We can also filter palindromes directly using boolean indexing without creating intermediate lists ?

import pandas as pd

data = {'Id': [1, 2, 3, 4, 5], 'Name': ['bob', 'peter', 'hannah', 'james', 'david']}
df = pd.DataFrame(data)
print("DataFrame is:")
print(df)

# Direct boolean indexing
result = df[df['Name'] == df['Name'].str[::-1]]
print("\nPalindrome names are:")
print(result)

DataFrame is:
   Id    Name
0   1     bob
1   2   peter
2   3  hannah
3   4   james
4   5   david

Palindrome names are:
   Id    Name
0   1     bob
2   3  hannah

Comparison

Conclusion

All three methods successfully filter palindrome names from a DataFrame. Boolean indexing is most efficient for large datasets, while list comprehension offers the best balance of readability and performance.