Checkpoint: pandas Foundations

Five questions on this section. Answer all of them, then see your score and why each answer is right or wrong.

After orders = pd.read_csv("orders.csv"), orders["order_date"].dt.month raises AttributeError: Can only use .dt accessor with datetimelike values. What is the fix?

Use orders["order_date"].month instead.
Sort the column first.
Load with parse_dates=["order_date"] (or convert with pd.to_datetime) so the column is datetime64.
Drop the rows with missing dates.

What does products.loc[products["unit_price"] > 100, "name"] return?

A DataFrame with every column for products above 100 dollars
A Series of the names of products priced above 100, indexed by their row labels
True or False for each product
The number of products priced above 100

Which line raises the price of active products by 5% and reliably updates products itself?

products[products["is_active"] == 1]["unit_price"] *= 1.05
products["unit_price"][products["is_active"] == 1] *= 1.05
products.unit_price * 1.05
products.loc[products["is_active"] == 1, "unit_price"] *= 1.05

What is the result of s1 + s2?

Python

s1 = pd.Series([10, 20], index=["a", "b"])
s2 = pd.Series([1, 2], index=["b", "c"])

a: NaN, b: 21, c: NaN
a: 11, b: 22
a: 10, b: 21, c: 2
A ValueError because the indexes differ

You want every order from the web or the mobile app. Which filter is the clearest correct choice?

orders[orders["channel"] == "web" or orders["channel"] == "mobile_app"]
orders[orders["channel"] == ["web", "mobile_app"]]
orders[orders["channel"].isin(["web", "mobile_app"])]
orders.loc["web":"mobile_app"]

5 questions unanswered