How can I add columns to a Pandas DataFrame?

How can I add columns to a Pandas DataFrame?

You can add columns to a Pandas DataFrame using the assignment operator. For example, df['new_column'] = value.

What if I want to add multiple columns at once?

You can use the assign() method or simply assign a dictionary of new columns to the DataFrame. For example, df = df.assign(col1=value1, col2=value2).

Can I add a column based on existing columns?

Yes, you can create a new column based on existing ones by performing operations. For example, df['new_col'] = df['col1'] + df['col2'].

What about adding a column with a default value?

You can add a column with a default value by simply assigning it like this: df['new_col'] = default_value.