How to Rename Pandas DataFrame Index

When working with Pandas DataFrames, it can be necessary to rename the index or column names for clarity or consistency. However, the df.rename() method has limitations when it comes to renaming the DataFrame index.

In the given example, the user attempted to rename the index and column name of a DataFrame using df.rename(), but only the column name was updated. This is because the rename() method takes a dictionary for the index, which applies to index values.

Instead, to rename the index level name, the following code should be used:

df.index.names = ['Date']

This assigns the name 'Date' to the index level.

It's important to remember that columns and index are both handled as objects of the same type (Index or MultiIndex). Therefore, you can interchange the two using the transpose method.

For a better understanding, consider the following examples:

# Create a DataFrame with named columns
df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=list('ABC'))

# Rename the index
df.index.names = ['index']

# Rename the columns
df.columns.names = ['column']

print(df)  # Output:
# column  A  B  C
# index
# 0       1  2  3
# 1       4  5  6

Note that the attribute for index names is just a list, and renaming can also be achieved using list comprehension or map.