How to Rename One or More Columns in Pandas Dataframe?

To rename one or more columns in a pandas DataFrame, you can use the rename function. Here are some examples of how to use it:

• 1. Rename a single column
• 2. Rename multiple columns
• 3. Rename columns in place
• 4. Rename columns with a function
• 5. Rename columns by index

1. Rename a single column

To rename a single column, you can use a dictionary to map the old column name to the new one. Here's an example:

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})

df = df.rename(columns={'A': 'new_column_name'})

print(df)

This will rename the column "A" to "new_column_name".

2. Rename multiple columns

To rename multiple columns, you can use a dictionary to map the old column names to the new ones. Here's an example:

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6], 'C': [7, 8, 9]})

df = df.rename(columns={'A': 'new_column_name_1', 'B': 'new_column_name_2'})

print(df)

This will rename the columns "A" and "B" to "new_column_name_1" and "new_column_name_2", respectively.

3. Rename columns in place

By default, the rename function returns a new DataFrame with the columns renamed. However, you can use the inplace parameter to modify the dataframe in place. Here's an example:

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})

df.rename(columns={'A': 'new_column_name'}, inplace=True)

print(df)

This will rename the column "A" to "new_column_name" in place.

4. Rename columns with a function

You can also use a function to rename the columns. The function will be applied to each column name, and the result will be used as the new column name. Here's an example:

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})

df = df.rename(columns=lambda x: x.lower())

print(df)

This will rename the columns to lowercase.

5. Rename columns by index

You can also rename columns by their index using the set_axis method. Here's an example:

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})

df = df.set_axis(['new_column_name_1', 'new_column_name_2'], axis=1)

print(df)

This will rename the columns by their index.

Overall, there are several ways to rename one or more columns in a pandas DataFrame. You can use a dictionary to map the old column names to the new ones, use a function to rename the columns, or rename the columns by index using the set_axis method. Choose the method that best fits your needs depending on your specific use case.