Renaming columns in Pandas - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of renaming columns in a pandas DataFrame?

Renaming columns helps make the data easier to understand and work with by giving columns clear, meaningful names.

beginner

Which pandas method is commonly used to rename columns?

The rename() method is used to rename columns in a pandas DataFrame.

intermediate

How do you rename multiple columns at once using pandas?

You pass a dictionary to rename() where keys are old column names and values are new names, like df.rename(columns={'old1': 'new1', 'old2': 'new2'}).

intermediate

What does the inplace=True argument do in rename()?

It changes the original DataFrame directly without needing to assign the result to a new variable.

intermediate

Can you rename columns by assigning a new list of column names directly? How?

Yes, by assigning a list of new column names to df.columns, like df.columns = ['new1', 'new2', 'new3']. The list length must match the number of columns.

Which pandas method is used to rename columns?

A change_columns()

B rename()

C set_columns()

D update_columns()

The correct method to rename columns in pandas is rename().

How do you rename a single column 'old' to 'new' using rename()?

A df.columns = {'old': 'new'}

B df.rename({'old': 'new'})

C df.rename(columns={'old': 'new'})

D df.rename_column('old', 'new')

You must pass a dictionary to the columns parameter: df.rename(columns={'old': 'new'}).

What happens if you use inplace=True in rename()?

A The DataFrame is changed directly without creating a new one

B A new DataFrame is returned with changes

C An error occurs

D Columns are renamed only temporarily

inplace=True modifies the original DataFrame directly.

How can you rename all columns at once?

A Assign a new list to df.columns

B Use df.rename() without arguments

C Use df.columns.rename()

D Use df.set_columns()

You can rename all columns by assigning a list of new names to df.columns.

What must be true about the list when assigning new column names to df.columns?

A List must be sorted alphabetically

B List can be shorter than columns

C List can contain duplicates

D List length must match number of columns

The list length must exactly match the number of columns in the DataFrame.

Explain how to rename columns in a pandas DataFrame using the rename() method.

Think about how you tell pandas which columns to rename and what to rename them to.

Describe two ways to rename columns in pandas and when you might use each.

One way changes some columns, the other changes all columns at once.