Pandas reset index - How to reset index Pandas

reset index in pandas dataframe and remove old index

In this post, I will show you how to reset index in Pandas DataFrame in Python. Often after doing data manipulation in pandas dataframe the manipulated data may contain row index name of the original dataframe.

We can use python pandas.reset_index() function to set index to the default integer index starting at 0.

pandas.reset_index

Syntax

DataFrame.reset_index(level=None, drop=False, inplace=False, col_level=0, col_fill='', allow_duplicates=_NoDefault.no_default, names=None)

Parameters

level: str, int, tuple or list (default None)
- Only remove the specified levels from the index. By default removes all levels
drop: bool (default False)
- Used for resetting the index to it’s default integer index
inplace: bool (default False)
- Whether to modify the DataFrame instead of creating a new one
col_level: str or int (default 0)
- if the columns contain multiple levels, determines the level at which the labels will be inserted. It is inserted into the first level by default.
col_fill: object (default ")
- if the columns contain multiple levels, determine the name of other levels. If value is None then the index name will be repeated
Returns: DataFrame containing the new index or None if inplace=True

How to reset index in pandas dataframe

Create a sample DataFrame

import pandas as pd
import numpy as np
import random

# Create dataframe with index

df = pd.DataFrame({
                    'Physics': [85, 74, 63, 88, 91],
                    'Chemistry': [69, 83, 73, 50, 61],
                    'Mathematic': [74, 82, 61, 72, 65]
                  }, index=['Rajesh', 'Nitesh', 'Neha', 'Sivam', 'Arti'])
df

Case 1: Pandas reset index to start at 0

df.reset_index()

After applying reset.index() function, the index name will be converted to a column name (in our example, student names). The default name of the column will be index.

Case 2: Rename Pandas DataFrame Index

Now as you can see the name of the converted column is index, but we want that column name to be Student_Name.

# reset index to column in pandas
df.index.rename('Student_Name', inplace=True)
df

Reset Index

df = df.reset_index()
df

Case 2: pandas reset index to start at 1

Now if you want to start the index from 1 instead of 0

df.index = np.arange(1, len(df) + 1)
df

Conclusion

In this pandas set index tutorial, I explained different ways of resetting the index in the pandas library of python:

Reset index name in pandas
pandas reindex from 0
pandas resetting index to start at 1
pandas remove index column

Pandas reset index – How to reset index Pandas