Final answer:
To change the index column name in a pandas DataFrame, use the .rename() method with the index parameter or set a new index with set_index().
Step-by-step explanation:
To change the index column name in a pandas DataFrame, you can use the .rename() method, providing a dictionary to the index parameter with the current index name as the key and the new index name as the value. For example, if you want to change the index name from 'old_index' to 'new_index', you would write:
df.rename(index={'old_index': 'new_index'}, inplace=True)
Alternatively, if you are setting a new index with a column from the DataFrame, you can directly set the index_col parameter in the read_csv() function or use the set_index() method and provide the new index column name:
df.set_index('new_column_name', inplace=True) It's important to note that the inplace=True parameter makes changes directly to the original DataFrame, eliminating the need to assign the modified DataFrame to a new variable.