Python Pandas - Return a sorted copy of the index

To return a sorted copy of the index, use the index.sort_values() method in Pandas. This method creates a new sorted index without modifying the original.

Basic Syntax

index.sort_values(ascending=True, return_indexer=False)

Creating and Displaying Index

First, let's create a Pandas index with unsorted values ?

import pandas as pd

# Creating Pandas index
index = pd.Index([50, 10, 70, 95, 110, 90, 30])

# Display the original index
print("Original Pandas Index...")
print(index)

Original Pandas Index...
Index([50, 10, 70, 95, 110, 90, 30], dtype='int64')

Sorting in Ascending Order

By default, sort_values() sorts in ascending order ?

import pandas as pd

index = pd.Index([50, 10, 70, 95, 110, 90, 30])

# Sort index values (ascending by default)
sorted_index = index.sort_values()
print("Sorted Index (Ascending)...")
print(sorted_index)

# Original index remains unchanged
print("\nOriginal Index unchanged...")
print(index)

Sorted Index (Ascending)...
Index([10, 30, 50, 70, 90, 95, 110], dtype='int64')

Original Index unchanged...
Index([50, 10, 70, 95, 110, 90, 30], dtype='int64')

Sorting in Descending Order

Set ascending=False to sort in descending order ?

import pandas as pd

index = pd.Index([50, 10, 70, 95, 110, 90, 30])

# Sort index values in descending order
sorted_desc = index.sort_values(ascending=False)
print("Sorted Index (Descending)...")
print(sorted_desc)

Sorted Index (Descending)...
Index([110, 95, 90, 70, 50, 30, 10], dtype='int64')

Working with String Index

The sort_values() method also works with string data ?

import pandas as pd

# Creating string index
str_index = pd.Index(['apple', 'zebra', 'banana', 'cherry'])

print("Original String Index...")
print(str_index)

# Sort string index
sorted_str = str_index.sort_values()
print("\nSorted String Index...")
print(sorted_str)

Original String Index...
Index(['apple', 'zebra', 'banana', 'cherry'], dtype='object')

Sorted String Index...
Index(['apple', 'banana', 'cherry', 'zebra'], dtype='object')

Key Points

Conclusion

Use sort_values() to create a sorted copy of a Pandas index. The method preserves the original index and supports both ascending and descending order sorting.