How to sort a Pandas DataFrame by index?

When there is an DataFrame like the following:

import pandas as pd df = pd.DataFrame([1, 1, 1, 1, 1], index=[100, 29, 234, 1, 150], columns=['A']) 

How can I sort this dataframe by index with each combination of index and column value intact?

2 Answers

Dataframes have a sort_index method which returns a copy by default. Pass inplace=True to operate in place.

import pandas as pd df = pd.DataFrame([1, 2, 3, 4, 5], index=[100, 29, 234, 1, 150], columns=['A']) df.sort_index(inplace=True) print(df.to_string()) 

Gives me:

 A 1 4 29 2 100 1 150 5 234 3 

Slightly more compact:

df = pd.DataFrame([1, 2, 3, 4, 5], index=[100, 29, 234, 1, 150], columns=['A']) df = df.sort_index() print(df) 

Note:

• sort has been deprecated, replaced by sort_index for this scenario
• preferable not to use inplace as it is usually harder to read and prevents chaining. See explanation in answer here: Pandas: peculiar performance drop for inplace rename after dropna