Adding and Dropping Columns

Adding columns

There are various ways you can add new columns to a DaraFrame.

Assign the same value to every row

Output:

Assigning a list or array

• Assign different values per row (length must match number of rows).

Output:

Using calculations on existing columns

• New columns can be derived from existing ones.
• Changes the original DataFrame.

Output:

Using .assign()

• Creates a new column (or multiple) without modifying the original.
• Can also be chained together.

Using .insert()

• Insert a column at a specific position.

Output:

Dropping columns

There are also various ways you can remove columns from a DataFrame.

Using .drop()

• Drops columns by name.

Drop multiple columns::

Key parameters:

• axis=1 → columns
• axis=0 → rows (default)
• inplace=True → modify the DataFrame directly

Using del

• Deletes a single column.

Using .pop()

• Removes a column and returns it.