Sometimes, we want to add a column to an existing DataFrame. We might want to add new information or perform a calculation based on the data that we already have.
One way that we can add a new column is by giving a list of the same length as the existing DataFrame.
Suppose we own a hardware store called The Handy Woman and have a DataFrame containing inventory information:
|Product ID||Product Description||Cost to Manufacture||Price|
|1||3 inch screw||0.50||0.75|
|2||2 inch nail||0.10||0.25|
It looks like the actual quantity of each product in our warehouse is missing!
Let’s use the following code to add that information to our DataFrame.
df['Quantity'] = [100, 150, 50, 35]
Our new DataFrame looks like this:
|Product ID||Product Description||Cost to Manufacture||Price||Quantity|
|1||3 inch screw||0.50||0.75||100|
|2||2 inch nail||0.10||0.25||150|
df contains information on products sold at a hardware store. Add a column to
'Sold in Bulk?', which indicates if the product is sold in bulk or individually. The final table should look like this:
|Product ID||Product Description||Cost to Manufacture||Price||Sold in Bulk?|
|1||3 inch screw||0.50||0.75||Yes|
|2||2 inch nail||0.10||0.25||Yes|